Separation union either. Compound sentences with disjunctive conjunctions

The Russian language is as beautiful as it is difficult. Moreover, both for foreigners and sometimes for those who speak it from early childhood. The biggest difficulties arise with the stylistic combination of words, spelling and, of course, punctuation. Many rules are complex in that they have many nuances and exceptions. For example, a comma before the conjunction “or”. This article will be devoted to a detailed analysis of this rule.

Why are conjunctions needed in Russian?

This performs a syntactic function, ensuring the connection of words into combinations that are also possible, but do not convey many important elements of meaning.

The classification of these parts of speech is very extensive. They can be simple and compound, single and double, paired and unpaired, etc. According to their function in a sentence, they are divided into two groups - coordinating and subordinating. And according to their meaning, they can be divided into more than 15 types, including explanatory, mode of action, purpose, connective, adversative, disjunctive and many others. We will consider the last of these types in this article. And we will focus in detail on one of the examples of disjunctive conjunctions, as well as the rules for its punctuation.

The meaning of the union

The meaning of this word conveys division or opposition. Such a conjunction is used when the situation being described excludes another.

For example, two objects or phenomena are contrasted:

She will buy milk or kefir.

The characteristics of any objects may be separated or contrasted:

Either he is brave or he is crazy.

Actions often become the object of opposition:

Open the door, or we'll break it down!

Most likely, you have already noticed that in some of the examples given there is a comma before the word “or”, while in others there is not. What influences this? First of all, the features of the proposal itself.

Single union with homogeneous members

Often a situation arises when individual members answer the same question and refer to the same word. These can be two (or more) predicates. Such members of the sentence are called homogeneous.

They can be separated by commas:

A quiet, gentle, melodic sound was heard.

They may be preceded by a colon:

There were dishes on the table: cups, plates, a teapot.

The conjunctions “and”, “a”, “but” are also often used. In some cases, homogeneous members are united by a disjunctive union. The meaning of such a sentence is to separate something similar (objects, signs).

Let's look at examples of how a comma is placed before “or” in such cases, and whether it is placed at all.

In good weather, they usually went on a picnic or walked around the neighborhood.

He was going to go to Paris or London.

The application can be typed on a computer or written by hand.

As we see, a conjunction with a separating function connects different types of homogeneous members of a sentence. Is there a comma before “or” in such cases? No, it is not installed.

Single conjunction in a complex sentence

The grammatical basis - subject and predicate - can be present not only in a single quantity. If a sentence has two (or more) such stems, it is called complex. Two parts can be united either in a non-union way or with the help of various unions, including separation ones. Is a comma necessary before “or” in a complex sentence? Let's look at examples.

Tomorrow we will go to the Petrovs, or they will visit us.

We need to act now, or it will be too late.

The examples clearly show that a comma before “or” connects parts of a complex sentence (two grammatical bases united by semantic unity). This punctuation mark is always necessary between such parts.

Double alliance (“either...or”)

Some sentences express an intensified opposition or separation of certain objects, actions, qualities. This function is performed by a double dividing union. As, for example, in the saying:

Sink or swim.

In this case, a comma is placed before “or” because a double conjunction is used. You can give an example with a simple sentence that has homogeneous members:

It will either rain or hail.

Likewise, a comma before “or” is necessary if we have a complex sentence:

Either you calm down or I'll leave.

In the latter case, this punctuation mark is required for two reasons:

• type of sentence (complex, two grammatical stems);
• double separation union.

So, is a comma needed before “or” if it is a double conjunction? Yes, always. This rule is not affected by accompanying grammatical circumstances.

When not to use a comma

We have dealt with several difficult cases. But a logical question arises: is a comma always placed before “or”?

As we have already understood, in a simple sentence this union does not require separation with a punctuation mark. For example:

The food could be tasty or tasteless.

What other similar cases are there?

For example, when there is a common element that unites all parts.

Look at the clouds: it will rain or hail soon.

Separation is also not required if the constituent elements of a complex sentence are indefinitely personal or have the same predicate form. For example:

I wanted to sleep or just felt cold.

It was getting dark or dawning - it was difficult to make out what time of day it was.

Sometimes there are cases when intonation is the unifying factor. For example, interrogative:

Would it be better to come back tomorrow or should we postpone until the day after tomorrow?

In the cases described above, there is a certain common element that unites the parts of the sentence. Under these conditions, there is no need for a comma before “or.”

Now let's look at other dividing unions. Many of them mean the same thing as the functional part of speech, which became the topic of this article.

Similar in meaning to the conjunction “or”

This part of speech may well replace the word “or”, since it expresses the same meaning: an alternative in the form of two (usually opposite) phenomena, properties or objects. For example:

Will you have tea or coffee?

I don't like it when it's too hot or too cold.

They can wait for you or go themselves.

She spends the summer in the city or in the country.

This union has cases of separation or non-separation. This will be discussed in more detail below.

When to use a comma

The isolation of this conjunction is similar to the rules by which a comma is placed before the word “or”. These are the cases:

• double conjunction “either - or”;
• difficult sentence;
• a double title for a work of art.

An example can be given for each of these situations:

Either he's stupid or he's faking it(double conjunction).

We have to leave early or the bus will leave without us.(difficult sentence).

"The Golden Key, or the Adventures of Pinocchio"(title of the work).

When not to use a comma

There are also rules governing the placement of punctuation marks in cases with a conjunction of similar meaning. There is no need to separate the “or” in the following situations:

• a simple sentence in which homogeneous members are connected by a single conjunction;
• a complex sentence with the presence of a common element for all component parts (member of a sentence, group of words, intonation).

An example of a sentence that fits the first case:

Everyone had already gone outside or gone to bed.

The second situation can be illustrated by the following examples:

Let's bake something for tea: a pie, buns or cookies.

Has it become quiet or have we simply stopped noticing the noise?

As we can see, disjunctive conjunctions are similar not only in the semantic meaning they express, but also in their grammatical functions and interaction with punctuation rules.

Other dividing unions

In addition to the auxiliary part of speech and its double variant, which became the topic of this article, there are a number of similar conjunctions that carry the same meaning. Here they are:

• otherwise;
• and then;
• either - or;
• not that - not that;
• this - that;
• whether - whether;
• or or.

Examples of sentences with these parts of speech clearly demonstrate that they are quite similar in meaning to each other. Compare:

She will cook fish or chicken.

Leave in a good way, otherwise you will be kicked out.

Be quiet, otherwise the child will wake up.

Either no one is home, or they don’t want to open the door.

It's either rain or snow outside.

One thing or another interferes with him.

Whether you want it or not, it doesn't matter.

He is either very brave or crazy.

We see that the rules for placing commas in disjunctive conjunctions are also very similar.

conclusions

The comma before “either”, “or” and other dividing conjunctions is a rather difficult issue. Not in all cases it is possible to unambiguously determine whether this punctuation mark is needed here or not.

If we are talking about a simple or complex sentence without any accompanying features, then the solution is more or less clear.

With homogeneous members, a single conjunction “or” is not isolated. The exception is when the union is double.

In a complex sentence, a comma before the disjunctive conjunction is usually required. But certain factors (general intonation, a unifying word or group of words, impersonal and vaguely personal sentence types) can create exceptions to this rule.

For this reason, it is necessary to carefully analyze the sentence and check the appropriateness of the arrangement. In controversial cases, it would be useful to consult a reference book on punctuation. The classic version of this was written by Professor D. E. Rosenthal.

Homogeneous are those members of a sentence that answer the same question and relate to the same member of the sentence or are explained by the same member of the sentence.

Compare two sentences:

I often getletters Andparcels . I oftenI get AndI'm sending letters

In the first sentence, two complements answer the question WHAT? and refer to the same predicate, and in the second sentence two predicates are explained by one common addition.

Homogeneous members are usually expressed by words of one part of speech, as was the case in the sentences above, but can also be expressed by different parts of speech. For example: He spoke slowly With long pauses. In this sentence, the first circumstance is expressed by an adverb, and the second by a noun with a preposition.

Homogeneous members in sentences can be extended, that is, they can have dependent words. Consider the following sentence carefully.

Guys filmedfrom the head of the cap andbowed.

Here there are two homogeneous predicates (REMOVED and BOWED): the first is common by circumstance (FROM THE HEAD) and the object (HATS), and the second is not common (it has no dependent words).

One sentence can have several rows of homogeneous members. For example:

The moon rose and illuminated the road, field and houses of the village.

The first row of homogeneous members in this sentence is created by predicates, the second - by complements.

Homogeneous and heterogeneous definitions

The same word in a sentence can have several definitions, which can be homogeneous or heterogeneous. It is necessary to learn to distinguish between these two types of definitions, since homogeneous definitions in writing are separated by commas, and a comma is not placed between heterogeneous definitions.

1. Homogeneous definitions are pronounced with enumerative intonation and characterize an object on one side: by color, shape, size, and so on.

In the morning the sun hits the gazebo through purple, lilac, green and lemon foliage(Paustovsky).

This sentence contains four definitions for the word FOLIAGE; they are uniform, since they all name the color and are pronounced with the intonation of enumeration.

Heterogeneous definitions characterize an object from different angles and are pronounced without enumerative intonation, for example:

It was an unbearably hot July day(Turgenev).

The definition of HOT tells us about the weather, and the definition of JULY tells us what month this day was in.

Please note that homogeneous definitions can be connected by coordinating conjunctions, and if there are no conjunctions, they can be easily inserted. Compare the three sentences below.

He spoke German, French, and English.
He spoke German, French and English.
He spoke German, French, and English.

2. Homogeneous definitions cannot be expressed by adjectives belonging to different lexical categories.

If definitions are expressed by adjectives, then you can determine whether they need to be separated by commas in the following way. It is known that adjectives are divided into three categories: qualitative, relative And possessive . If one word has definitions expressed by adjectives of different categories, then these definitions will be heterogeneous.

His old woman is standing on the porchExpensive sablewarmer jacket(Pushkin).

The word DUSHEGREYKA has two definitions: DEAR (qualitative adjective) and SOBOLEY (relative adjective).

3. Definitions are considered heterogeneous if one definition is expressed by a pronoun or numeral, and the other by an adjective.

Look at the examples in the illustration.

Why don't you put it onyours newdress?
Finally we have waitedfirst warmdays.

4. Sometimes in works of art there may be sentences in which there are commas between definitions that characterize the subject from different sides.

Read sentences from the works of I. A. Bunin and A. P. Chekhov. In them, the authors strive to create a single, holistic idea of ​​an object or phenomenon, and such definitions can be considered homogeneous.

Has arrivedrainy, dirty, darkautumn(Chekhov).
Clear days have changedcold, bluish-gray, soundless(Bunin).

Punctuation in sentences with homogeneous members connected by coordinating conjunctions

Coordinating conjunctions in Russian speech are divided into three categories: connective, divisive and adversative.

Meaning connecting unions can be conventionally designated by the phrase: “BOTH THIS AND THAT.” They connect two homogeneous members to each other. Meaning dividing conjunctions can be defined as follows: “EITHER THIS OR THAT.” Such unions indicate the possibility of only one homogeneous member out of several or their alternation. Meaning adversative unions is expressed differently: “NOT THIS, BUT THIS.” Opposite conjunctions contrast one homogeneous member with another. Consider examples of conjunctions of each category in the illustration.

Please note that the conjunction YES is written both in the column with connecting conjunctions and in the column with adversative conjunctions. The fact is that it can be used in two meanings. Compare two sayings: Without thread Yes needles cannot sew fur coats And Small spool Yes roads. In the first saying, the conjunction YES can be replaced by AND, and in the second - by BUT.

Some coordinating conjunctions consist of several words, for example, AS... AND; NOT ONLY... BUT ALSO. Such unions are called compound.

The placement of commas in sentences where homogeneous members are connected by coordinating conjunctions depends on what category they belong to.

Before coordinating conjunctions connecting homogeneous members, a comma is placed in three cases:

1) if in a sentence homogeneous members are connected by an adversative conjunction:
The berry is red,Yes tastes bitter. The task is difficultbut interesting;

2) if homogeneous members are connected by repeating unions:
It's noisy in the forest alone,And creepy,And funny(Fet);

3) if homogeneous members are connected by compound unions:
There will be a holidayNot only Today,but also Tomorrow..

Now let's turn to cases when there is no need to put a comma before conjunctions connecting homogeneous members.

1. If homogeneous members are connected by a single connecting or dividing conjunction, for example:

Minnows were splashing in the cageAnd perches.
In this forest in the pine trees you may notice a squirrelor woodpecker.

2. If unions combine homogeneous members into pairs, for example:

There were many knives in his collection And daggers, pistols And guns, decorated with precious stones.

3. If two homogeneous members are connected by repeating unions, but form a stable combination: BOTH DAY AND NIGHT, AND LAUGHTER AND SIN, NEITHER YES NOR NO, NEITHER TWO AND A AND A HALF, NEITHER BACK NOR FORWARD and others.

We were woken upneither lightneither dawn.

Punctuation marks in sentences with generalizing words

Read the proposal carefully.

Conifers grew near the housetrees: spruce, pine, fir.

In this example there are four subjects, but it is impossible to call them all homogeneous, because the first of them - the word TREES - unites the subsequent ones in its meaning, or, conversely, the last three subjects specify and clarify the meaning of the first. Between the first subject and the subsequent ones, you can insert the question: “Which ones exactly?”

If one of the words in a sentence is specified, clarified by a number of homogeneous members, then such a word is called generalizing . Please note: the generalizing word is the same member of the sentence as the homogeneous members.

Generalizing words in sentences can be expressed by different parts of speech, but pronouns are especially often used in this capacity, for example:

Neither noble family, nor beauty, nor strength, nor wealth - nothing can escape trouble.(Pushkin) or It has always been this way: a hundred and three hundred years ago.

Generalizing words can also be expressed as whole phrases, for example:

Every day old Moses began to bringvarious large fish : pike, ide, chub, tench, perch(Aksakov).

In this sentence, the combination will be DIFFERENT LARGE FISH.

In sentences with generalizing words, punctuation marks are placed in accordance with the rule of three main points.

1. If a generalizing word comes before homogeneous members, then a colon is placed after it.

Yellow maple leaves layeverywhere : cars.

2. If a generalizing word comes after homogeneous members, then a dash is placed in front of it.

On paths, on benches, on roofs cars – everywhere yellow maple leaves lay.

3. If a generalizing word comes before homogeneous members, and after them the sentence continues, then a colon is placed after the generalizing word, and a dash is placed after the homogeneous members.

Everywhere : on paths, on benches, on roofs cars – yellow maple leaves lay.

Exercise

He lay on his back and looked at the sky for a long time.

The outlines of trees, sprinkled with rain and agitated by the wind, began to emerge from the darkness (Turgenev).

Exhausted_dirty_wet, we reached the shore (According to Turgenev).

In the deep silence, the clinking of a nightingale (Bunin) could be heard clearly and cautiously throughout the garden.

I collected my goodies and returned to my sister (Bunin).

Dew glistened on the wet, fragrant, thick flowers and herbs (Bunin).

The clatter of hooves and the ringing of wheels echoed with thunder and reverberated from four sides (According to Gogol).

Songs and screams were heard louder and louder through the streets (Gogol).

We took a rubber inflatable boat with us and at dawn we went beyond the edge of the coastal water lilies to fish. (Paustovsky)

The waiter put cold and hot appetizers on the table, as well as the main dish - stuffed salmon.

From somewhere outside came the restlessly growing, mighty, menacing noise of a huge crowd (Babel).

I threw a heavy lead sinker at the she-wolf (Paustovsky).

From here one could see a large neglected garden (A. Gaidar).

The menu offered a large selection of white_red wine_ as well as carbonated drinks_ and juices.

Evgeny Schwartz grew up in the small provincial southern city of Maykop.

In the depths of the garden stood an awkward two-story shed, and under the roof of this shed fluttered a small red flag (Gaidar).

It’s especially good in the gazebo on quiet autumn nights, when the leisurely, vertical rain rustles in a low voice in the garden (Paustovsky).

There are many gas_electric stoves_ and ovens on display at the exhibition.

Ahead is a deserted September day (Paustovsky).

He packed not only clothes but also books into the suitcase.

He decided to pack either clothes or books in his suitcase.

He took out a suitcase and put there_ shirts_ and ties_ and an album with photographs.

The album contained photographs of his wife_ and relatives_ and friends.

In the depths of the garden there was a small outbuilding with small windows that did not open either in winter or in summer.

There were already pies_ and pancakes, pancakes_ and cheesecakes on the table.

I'll order_ either ice cream_ or strawberry juice.

I'll order ice cream_ or strawberry pie_ or cheesecake.

I will order_ not only ice cream_ but also apple pie.

Before, Yegorushka had never seen steamboats, locomotives, or wide rivers (Chekhov).

He is well acquainted with the life of the landowner and the peasant and bourgeois (Turgenev).

On the left side you can see vast fields, forests, three or four villages, and in the distance the village of Kolomenskoye with its high palace (Karamzin).

And the deceptive wave of the blue sea in the hours of fatal bad weather_ and the sling_ and arrow_ and the crafty dagger_ spare the winner for years (Pushkin).

The palisade was hung with bunches of dried pears and apples and airy carpets (according to Gogol).

There were a lot of flowers growing there: crane peas, porridge, bluebells, forget-me-nots, field carnations (Turgenev).

He knows a lot about everything that is important_ and interesting for a Russian person_ in horses_ and in cattle_ in the forest_ in bricks_ and in dishes_ in red goods_ and in leather goods_ in songs_ and dances (Turgenev).

The hare has many enemies: the wolf and the fox and man.

Whether at home or on the street or at a party, he felt someone’s gaze on him everywhere.

Tatyana prepared everything necessary for embroidery: multi-colored threads, beads, sequins, beads.

In our department store you can purchase various_ hats_ caps_ hats_ winter_ and sports hats.

Everywhere_ in the club_ on the streets_ on benches at the gates_ in houses_ noisy conversations took place (Garshin).

Everything merged, everything mixed up: earth_ air_ sky.

The next day, very tasty crayfish pies and lamb cutlets (Chekhov) were served for breakfast.

There were no human feelings left in him - neither love for his son nor compassion for his neighbor.

Deciduous trees_ aspen_ alder_ birch_ are still bare (Soloukhin).

The dew drops shimmered with all the colors of the rainbow: red_ yellow_ green_ purple.

It was joyfully young both in heaven and on earth and in the heart of man (Tolstoy).

1. _ and fatal secrets of the grave, fate_ and life in their turn_ everything was subject to their judgment (Pushkin).

And the shepherd driving the cows and the land surveyor riding in a chaise across the dam and the gentlemen walking all look at the sunset and every single one of them finds that it is terribly beautiful, but no one knows or will say what the beauty is (Chekhov).

And the fact that they were sitting in the living room, where everything, the chandelier in its case, and the armchairs, and the carpets underfoot, said that these same people, who were now looking out of the frames, had once walked, sat, and drank tea, and the fact that it was now silent here beautiful Pelageya walked - it was better than any stories (Chekhov).

Sometimes it happens that the clouds crowd in disarray on the horizon, and the sun, hiding behind them, paints them and the sky in all sorts of colors: crimson, orange, gold, purple, dirty pink; one cloud looks like a monk, another like a fish, the third like a Turk in a turban (Chekhov).

The glow covered a third of the sky, glitters in the church cross_ and in the glass of the manor's house_ reflects in the river_ and in the puddles_ trembles in the trees; far, far away against the background of dawn a flock of wild ducks is flying somewhere to spend the night... (Chekhov).

Imagine... a cropped head with thick, low-hanging eyebrows, a bird's nose, a long gray mustache, and a wide mouth, from which a long cherry chibouk protrudes; this head is clumsily glued to a skinny, hunchbacked body, dressed in a fantastic suit, a scanty red jacket and wide, bright blue trousers; this figure walked with his legs apart and shuffling shoes, spoke without removing his chibouk from his mouth, and carried himself with purely Armenian dignity, did not smile, did not widen his eyes, and tried to pay as little attention to his guests as possible.

A good conductor, conveying the composer’s thoughts, does twenty things at once: reads the score, waves his baton, follows the singer, moves towards the drum, then the horn, and so on. (Chekhov).

Alien people_ alien nature_ pathetic culture_ all this, brother, is not as easy as walking along Nevsky in a fur coat, arm in arm with Nadezhda Fedorovna_ and dreaming of warm lands (Chekhov).

Hatred for von Koren_ and anxiety_ all disappeared from the soul (Chekhov).

Complex sentences- These are sentences consisting of several simple ones.

The main means of connecting simple sentences into complex ones are intonation, conjunctions (coordinating and subordinating) and allied words (relative pronouns and pronominal adverbs).

Depending on the means of communication, complex sentences are divided into allied And non-union. Union proposals are divided into compound And complex.

Compound Sentences (SSPs) are complex sentences in which simple sentences are linked to each other by intonation and coordinating conjunctions.

Types of compound sentences by nature of the conjunction and meaning

SSP type	Unions	Examples
1. connecting unions(connective relations).	AND; Yes(in meaning And); no no; yes and; Same; Also; not only but.	They opened the door and air from the yard steamed into the kitchen.(Paustovsky). Her face is pale, her slightly parted lips have also turned pale.(Turgenev). Not only was there no fish, but the rod didn’t even have a fishing line(Sadovsky). He didn’t like jokes, and even her in front of him left alone(Turgenev).
2. Compound sentences with adversarial conjunctions(adverse relationships).	A; But; Yes(in meaning But); however(in meaning But); but; but; and then; not that; or else; particle(in the meaning of the union A); particle only(in the meaning of the union But).	Ivan Petrovich left, but I stayed(Leskov). Beliefs are instilled by theory, behavior is shaped by example.(Herzen). I didn't eat anything, but I didn't feel hungry(Tendryakov). It rained in the morning, but now the clear sky was shining above us(Paustovsky). You today gotta talk with his father, otherwise he will worry about your departure(Pisemsky). The boats immediately disappear into the darkness, only splashes of oars and the voices of fishermen can be heard for a long time(Dubov).
3. Compound sentences with dividing unions(separation relations).	Or; or; not that..., not that; then..., then; either... or...	Either eat the fish or run aground(proverb). Either he was jealous of Natalya, or he regretted her(Turgenev). Either the silence and loneliness had an effect on him, or he just suddenly looked with different eyes at the environment that had become familiar(Simonov).

Note!

1) Coordinating conjunctions can connect not only parts of a complex sentence, but also homogeneous members. Their distinction is especially important for punctuation marks. Therefore, when analyzing, be sure to highlight the grammatical basics in order to determine the type of sentence (simple with homogeneous members or complex sentence).

Wed: A man walked from a smoky ice hole and carried a large sturgeon(Peskov) - a simple sentence with homogeneous predicates; I'll give you money for the trip, and you can call a helicopter(Peskov) is a complex sentence.

2) Coordinating conjunctions usually take place at the beginning of the second clause (the second simple sentence).

In some places the Danube serves as a border, but it serves and is expensive people to each other(Peskov).

The exception is unions, too, also, particles-unions, only. They necessarily occupy or can occupy a place in the middle of the second part (the second simple sentence).

My sister and I cried, my mother also cried(Aksakov); His comrades treated him with hostility, but the soldiers truly loved him.(Kuprin).

Therefore, when parsing, such complex sentences are often confused with non-union complex sentences.

3) The double conjunction not only..., but also expresses gradational relations and is classified as a connecting conjunction in school textbooks. Very often, when parsing, only the second part is taken into account ( but also) and are mistakenly classified as adversative conjunctions. To avoid making mistakes, try replacing this double conjunction with the conjunction and.

Wed: Language should not only be understandable or simple, but also language must be good (L. Tolstoy). - Language must be understandable or simple, and language must be good.

4) Compound sentences are very diverse in meaning. Quite often they are close in meaning to complex sentences.

Wed: If you leave, it will become dark(Shefner). - If you leave, it will become dark; I didn't eat anything, but I didn't feel hungry(Tendryakov). - Although I didn't eat anything, I didn't feel hungry.

However, during analysis, it is not this specific meaning that is taken into account, but the meaning determined by the type of coordinating conjunction (conjunctive, adversative, disjunctive).

Notes In some textbooks and manuals, complex sentences include complex sentences with explanatory conjunctions that is, namely, For example: The board authorized him to speed up the work, that is, in other words, he authorized himself to do this(Kuprin); Bird flights developed as an adaptive instinctive act, namely: it gives birds opportunity to avoid unfavorable winter conditions(Peskov). Other researchers classify them as complex sentences or separate them into an independent type of complex sentences. Some researchers classify sentences with particles only as non-union sentences.

Often writers have a question about whether a comma is placed before “or” or not. The reason for doubt is that this is not a very common conjunction, which, moreover, belongs to the category of disjunctive conjunctions, and they, unlike adversative ones, are not so clear regarding punctuation with them. So, let's look at different cases when this word is separated by commas or not.

The word “or” is separated by commas

Before the word

1. Since “or” is a disjunctive conjunction, synonymous with “or” and used in almost the same way, a comma is needed before “or” in a complex sentence (except for the cases discussed below).

• We will arrive tomorrow at five o'clock in the evening, or you can come on Sunday morning.
• Every lesson, Fedor was obliged to approach the teacher and submit his disciplinary diary, or the teacher himself demanded a diary for some violation.

2. There will be a comma even if the conjunction is repeated. If so, it does not matter whether it is a complex sentence or homogeneous members. You just need to be careful not to put an extra comma before the first homogeneous member or part of a complex: it is not needed, even if there is also an “or” in front of it.

• On the weekend we are going to either the circus or the theater.
• Either he will pass the test in geography, or he will be expelled from the gymnasium.

No comma needed

1. A comma is not placed before a single conjunction “or” if it connects homogeneous members of the sentence.

• Pay for your purchase by credit card or cash.
• Please bring milk or kefir.

2. In a complex sentence, a comma is not placed before the conjunction “or” if the parts of the complex have common minor members or a common part.