Joining Sentences: и, а, но, потому́ что | Russian Grammar

Once you can build a simple sentence, the next step is connecting two of them. Russian does this with a small set of connector words, and choosing the right one is where English speakers stumble — partly because Russian splits "but" into two different words (а and но), and partly because the punctuation rules are stricter than in English. This page walks through the five connectors you need first: и (and), а (whereas), но (but), потому́ что (because), and поэ́тому (so/therefore).

и — simple addition ("and")

И joins two things that go together — two actions, two items, two facts — with no contrast between them. It's the plain "and."

Я чита́ю и пишу́.

I read and write. (two actions piled together, no contrast)

Она́ купи́ла хлеб и молоко́.

She bought bread and milk.

A key punctuation rule: a single и takes no comma before it. Russian, unlike English, does not use a comma in a simple "X and Y" list before the final и.

а — contrast/whereas (the one English lacks)

This is the connector with no clean English equivalent, and the one you'll get wrong most. А sets two different things side by side — not as an obstacle, but as a comparison: "this is one way, whereas that is another." English usually translates it as "and," sometimes "but," sometimes "whereas," but none of those is exact.

Я люблю́ чай, а он — ко́фе.

I like tea, whereas he likes coffee. (two parallel facts contrasted side by side — а, not но)

Э́то не соба́ка, а ко́шка.

That's not a dog, but a cat. (correcting one thing into another — classic а)

Я рабо́таю, а ты отдыха́ешь.

I'm working, whereas you're resting. (you against me — comparison, not obstacle)

The test: if you could say "whereas" or "while" in English — if you're lining up two things to compare them — use а. А always takes a comma before it.

но — "but" of obstacles

Но is the "but" of a thwarted expectation or an obstacle: you'd expect one thing, but reality gets in the way. This is what English speakers usually mean by "but."

Хочу́, но не могу́.

I want to, but I can't. (desire blocked by an obstacle — classic но)

Кварти́ра ма́ленькая, но ую́тная.

The flat is small but cosy. (you'd expect 'small' to be a downside, но overturns that)

The distinction with а is real and worth drilling: а compares, но obstructs. Я люблю́ чай, а он ко́фе just lines up two preferences (no conflict). Хочу́, но не могу́ pits desire against inability (a conflict). Но also always takes a comma before it.

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The English "but" maps onto both а and но. Ask: am I just comparing two things (whereas) or am I overturning an expectation (obstacle)? Comparison → а. Obstacle → но. This single question resolves most а/но mistakes. The deeper treatment is on coordinating и, а, но.

потому́ что — "because" (the cause)

To give the reason for something, use потому́ что ("because"). The cause-clause comes after it, and there is a comma before потому́ что.

Я не пришёл, потому́ что заболе́л.

I didn't come because I got sick. (the reason follows потому́ что)

Она́ ра́да, потому́ что сдала́ экза́мен.

She's happy because she passed the exam.

You can also split it for emphasis (Я не пришёл по́тому, что заболе́л — "the reason I didn't come is that..."), but as a beginner keep потому́ что together as one block.

поэ́тому — "so / therefore" (the result)

Поэ́тому is the mirror image of потому́ что: instead of giving the cause, it gives the result. Compare English "because" (cause) vs. "so" (result) — same logical link, viewed from opposite ends.

Я заболе́л, поэ́тому не пришёл.

I got sick, so I didn't come. (the result follows поэ́тому — same facts as the потому́ что example, flipped)

Магази́н был закры́т, поэ́тому я верну́лся домо́й.

The shop was closed, so I went back home.

Notice the pair: Я не пришёл, потому́ что заболе́л = Я заболе́л, поэ́тому не пришёл. Cause-first uses потому́ что; result-first uses поэ́тому. (Both belong to the family covered on causal and conditional conjunctions.)

Building up: from two sentences to one

Watch two simple sentences merge with each connector:

Я уста́л. Я лёг спать. → Я уста́л, поэ́тому лёг спать.

I was tired. I went to bed. → I was tired, so I went to bed.

Я хоте́л пойти́. Шёл дождь. → Я хоте́л пойти́, но шёл дождь.

I wanted to go out. It was raining. → I wanted to go out, but it was raining.

A note on commas

Russian punctuation is stricter than English: а, но, потому́ что, and что always take a comma before them. The only common exception is a single connecting и, which takes no comma. This rule is mechanical, so lean on it.

Connector	Meaning	Comma before it?
и	and (addition)	No (single и)
а	whereas (comparison)	Yes
но	but (obstacle)	Yes
потому́ что	because (cause)	Yes
поэ́тому	so / therefore (result)	Yes

Common Mistakes

❌ Я люблю́ чай, но он лю́бит ко́фе.

Wrong choice — there's no obstacle here, just two preferences compared side by side. Use а.

✅ Я люблю́ чай, а он лю́бит ко́фе.

I like tea, whereas he likes coffee.

❌ Хочу́, а не могу́.

Wrong — this is a thwarted desire (an obstacle), not a side-by-side comparison. Use но.

✅ Хочу́, но не могу́.

I want to, but I can't.

❌ Я чита́ю, и пишу́.

Wrong punctuation — a single connecting и takes no comma before it.

✅ Я чита́ю и пишу́.

I read and write.

❌ Я не пришёл потому́ что заболе́л.

Missing comma — потому́ что always takes a comma before it.

✅ Я не пришёл, потому́ что заболе́л.

I didn't come because I got sick.

Key Takeaways

и = simple addition ("and"), and a single и takes no comma.
а = side-by-side comparison ("whereas") — Russian's own connector with no clean English match.
но = "but" of an obstacle / thwarted expectation.
The English "but" splits into а (compare) vs. но (obstruct) — ask "whereas or obstacle?"
потому́ что gives the cause; поэ́тому gives the result (Я заболе́л, поэ́тому не пришёл).
A comma goes before а, но, потому́ что, and что — always.

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