In short

A безсполучнико́ве складне́ ре́чення is a multi-clause sentence whose clauses carry no conjunction between them (no і, а, але, бо, що, коли). The relationship between the clauses is signalled instead by two things: the punctuation mark at the seam and the meaning (plus intonation). Ukrainian has four such seams — comma, semicolon, colon and dash — and each one stands in for a whole family of conjunctions you deliberately left out. Choosing the right mark is therefore a grammar decision, not a typographic one.

The quickest route to the correct mark is a test conjunction: mentally slot a conjunction into the gap and see which one fits. «і» (at the same time / then) → comma; «бо / а саме / що» (because / namely / that) → colon; «тому / але / коли / якщо» (so / but / when / if) → dash.

The rule

1. Comma «,» — simultaneity or enumeration. Use it when the clauses simply list events that happen together or in sequence and are closely bound. This is the Ukrainian equivalent of what English calls (and forbids as) a “comma splice” — here it is fully correct.

2. Semicolon «;» — a looser or heavier list. Use it when the enumerated clauses are more independent from one another, are internally long, or already contain their own commas. Its test conjunction is the comma’s own «і», so the semicolon is picked by weight, not meaning: short bound parts keep the comma (Хма́ри розійшли́ся, ви́глянуло со́нце), and «;» waits until a part grows long or carries commas of its own.

3. Colon «:» — the second clause explains the first. The colon points backwards: the part after it reveals a cause (test: бо / тому що), gives a specification (test: а саме), or states the content of a verb of perception or speech in the first clause (test: що — I see / know / feel that…).

4. Dash «—» — the second clause is driven by the first. The dash points forwards: the part after it is a result (test: тому / так що), a contrast (test: а / але), or the main clause of a time / condition whose first part is the «коли / якщо» clause. The dash also marks a rapid succession of events.

The colon-vs-dash choice is the heart of the topic: colon = ”…, because/namely/that …”; dash = ”…, so/but/if-then …”. Say the sentence aloud — the colon has a held, warning pause; the dash has an abrupt drop and a jump.

Forms & patterns

The “paradigm” here is the four marks and the conjunctions each one replaces.

The colon in detail — three explanatory relations:

The dash in detail — four driving relations:

Note that the dash covers the widest ground of all: a single mark can mean so, but, if… then or the next instant. Let the meaning, not one fixed rule, decide which reading applies.

Examples

Common mistakes

• Насува́ються хма́ри, бу́де дощ. -> Насува́ються хма́ри — бу́де дощ. — the second part is a prediction / result (test: тому), which takes a dash, not a plain comma.
• Не запі́знюйся, по́їзд не чека́тиме. -> Не запі́знюйся: по́їзд не чека́тиме. — the second clause states the reason (test: бо), so a colon is required.
• Я відчу́в — насува́ється гроза́. -> Я відчу́в: насува́ється гроза́. — after a verb of perception the explanatory clause takes a colon (test: що), not a dash.
• Пішо́в дощ: ми змо́кли. -> Пішо́в дощ — ми змо́кли. — the second clause is the consequence of the first (test: тому), so a dash; a colon would wrongly say it explains the first.
• Була́ ніч. Ішо́в дощ. -> Була́ ніч, ішо́в дощ. — two tightly linked simultaneous facts belong in one asyndetic sentence joined by a comma; the English fear of a “comma splice” does not apply in Ukrainian.

Tips

• Run the test-conjunction check every time: which of «і / бо / а саме / що / тому / але / якщо» fits the gap? The family it belongs to picks the mark.
• Remember the direction: a colon looks back (”:” = because / namely / that), a dash looks forward (”—” = so / but / if-then / and-next). The reason goes after the colon (Мовчу́: нема́ чого сказа́ти); the consequence goes after the dash (Уда́рив грім — усі́ здригну́лися).
• Reach for the semicolon only when the clauses are loosely related or already carry their own commas — it separates without binding them tightly.
• Trust your intonation (lesson on Intonation): the explanatory colon is a held, expectant pause; the dash is a sharp fall followed by a lift. If you can hear it, you can punctuate it.
• If a conjunction like «і» or «а» would sit there naturally and you keep it, you have written a compound sentence, not an asyndetic one — the defining feature here is that the conjunction is absent.
• Asyndetic sentences read as dynamic and compact; they are common in narrative, proverbs and headlines, and rarer in dry official prose (see Functional styles).