Якщо vs Якби ('if')

English "if" is a single word doing three different jobs, and Ukrainian splits them. For a real, open condition ("if you come, we'll talk") Ukrainian uses якщо́ with the indicative. For an unreal, hypothetical or counterfactual one ("if I had time, I would come") it uses якби́ with the conditional particle би/б in both clauses. And for an indirect "whether" inside a reported question ("I don't know if she'll come") it uses neither — it uses чи. This is the decision page; the mechanics of the conditional particle are on the conditional formation page, and чи lives on the indirect questions page.

The quick answer

Use якщо́ when the condition is real and possible — a genuine future or present that may well come true. The verbs stay in the indicative, usually the future: Якщо́ ти при́йдеш, ми пого́воримо. Use якби́ when the condition is unreal — hypothetical, imagined, or contrary to fact. Both clauses go into the conditional with the particle би / б: Якби́ я мав час, я б прийшо́в. The test: is the condition a genuine possibility (якщо́) or contrary-to-fact / imagined (якби́)?

Decision tree

Step 1: Could the condition really happen? → якщо́ + indicative

If the "if" describes something that might genuinely come true — a real future plan, an open possibility — use якщо́, and keep the verbs in the indicative. Ukrainian is stricter than English here: where English says "if you come" with a present-tense verb, Ukrainian uses the future for a future condition (Якщо́ ти при́йдеш…), because the coming is genuinely yet to happen.

Step 2: Is the condition imagined or contrary to fact? → якби́ + би/б in both clauses

If the "if" describes something hypothetical or untrue — a daydream, an impossible wish, a "what if things were different" — use якби́, and put the conditional particle би / б in both clauses. The verbs are the past-tense base (which is where the conditional is built from), and the particle is б after a vowel, би after a consonant.

Step 3: The real-vs-unreal test in one move

Translate your sentence two ways and see which English fits: if "if you come, we'll talk" works (a real plan), it is якщо́; if "if you came / had come, we would talk" works (you probably won't / didn't), it is якби́. English marks the same split with the subjunctive backshift — "if I have" vs "if I had / had had" — so use your own instinct: a backshifted, "this is hypothetical" English "if" maps to якби́.

The two sentences differ only in how the speaker frames the call: as something that may really happen (якщо́) or as a hypothesis (якби́). That framing — not the English tense alone — is what you are choosing.

Step 4: "Past unreal" and "present unreal" use the same якби́ form

Ukrainian does not split the unreal conditional into a present and a past form the way English does ("if I had / if I'd had"). One якби́ + past + би/б form covers both, and the time is read from aspect and context — usually a time word like учо́ра or за́втра.

So do not hunt for a separate "past conditional" — Ukrainian has none. Pick the aspect that fits and let the time word carry the rest. There is also a stylistic variant коли́ б that means the same as якби́ ("if only / were it that"), common in wishes and a touch more literary: Коли́ б ти знав, як я скуча́в. ("If only you knew how I missed you.")

The чи warning: indirect "whether" is neither якщо́ nor якби́

Here is the trap that catches English speakers cold. English uses "if" for a third thing entirely — the indirect question, where "if" means "whether": "I don't know if she'll come," "I wonder if it's true." This is not a condition and takes neither якщо́ nor якби́. It takes чи.

Source-language comparison

For an English speaker, the single English word "if" fans out into three Ukrainian words, and you must sort which job it is doing before you translate. Real condition ("if you come, we'll go") → якщо́ with the future. Unreal condition ("if you came / had come, we would go") → якби́ with past + би/б in both clauses. Indirect question ("I wonder if it's true," "I don't know if she'll come") → чи. The good news is that English already marks the first two with its own subjunctive backshift — "if I have" vs "if I had" — so your instinct is reliable; you just have to remember the third, чи, which English hides under the same "if." Mixing them — якщо́ for a hypothesis, or якщо́ for a "whether" — is one of the most frequent learner errors.

For a Russian speaker, the mapping is clean: е́сли → якщо́, е́сли бы → якби́, ли → чи. The mechanics transfer (past + the particle in the unreal), but the Ukrainian particle is би / б with its euphonic rule, and чи is the standard "whether," used more readily than the Russian enclitic ли.

Common Mistakes

Key Takeaways

• якщо́ = a real / open condition with the indicative (usually the future): Якщо́ ти при́йдеш, ми пого́воримо.
• якби́ = an unreal / counterfactual condition with past + би/б in both clauses: Якби́ я мав час, я б прийшо́в.
• The particle би/б appears twice in a якби́ sentence — fused into якби́ and again in the result clause (я б…). Dropping the second one is the top error.
• One якби́ form covers both present-unreal and past-unreal; aspect and context (за́втра / учо́ра) supply the time. Коли́ б is a more literary variant.
• English "if" also covers indirect "whether" — that is чи, never якщо́/якби́: Не зна́ю, чи вона́ при́йде.