vařit / uvařit — to cook, to boil

"To cook" — and, as it happens, "to boil" — is the aspect pair vařit / uvařit. The imperfective vařit is for cooking as an activity or a habit: what you do every evening, what's bubbling on the stove right now. The perfective uvařit packages one act of cooking as finished, with a meal on the table at the end. This is one of the friendliest pairs in Czech: both halves are perfectly regular, they share a stem, and the perfective just bolts on the empty prefix u-.

The two halves, conjugated side by side

Both verbs belong to the -í- conjugation (the prosí / trpí type, traditional Class IV): the present runs on -ím, -íš, -í endings, and — a hallmark of this class — the 3rd person singular and plural look identical (vaří = "he cooks" and "they cook"). The perfective is just vařit with u- in front, and, as always, the perfective "present" is really a future.

For the full machinery of this conjugation class, see the -í- class (prosí).

Present meaning vs future meaning

This is the trap every aspect pair sets. Vařím is a genuine present — a habit or an action unfolding now. Uvařím, despite its present-tense shape, looks forward to a single finished result.

That second sentence must use the imperfective vaříš — the cooking is happening before your eyes. Swap in uvaříš and it would mean "what will you cook (and finish)?", not "what are you cooking now?"

Two meanings: cooking food and boiling liquid

vařit covers both English verbs that English keeps apart: to cook (prepare food by heating) and to boil (heat a liquid, or have it heat up).

• Cooking food: vařit oběd, vařit polévku, vařit kávu — make lunch, soup, coffee.
• Boiling a liquid (transitive): vařit vodu / uvařit vodu — boil water, bring it to the boil.
• Boiling intransitively (the liquid itself): voda vaří — "the water is boiling."

What the verb governs: accusative, and si for your own benefit

The thing you cook is a plain accusative object, no preposition: vařit oběd, uvařit polévku.

To say you cook something for yourself, add the reflexive si — the dative "for one's own benefit." Uvařím si čaj = "I'll make myself a tea." This little si is everywhere in Czech kitchen talk, and it changes the flavor of the sentence from a neutral act to one done for your own sake.

For the wider use of this reflexive dative, see reflexive si.

The past tense

Both verbs build the past from the l-participle plus the auxiliary, agreeing in gender and number. The aspect difference survives: vařil jsem = "I was cooking / used to cook"; uvařil jsem = "I cooked (and it was done)." Mind the neuter plural -a.

The imperative

The command also splits by aspect. Imperfective vař points to a habit, a manner, or an ongoing duty; perfective uvař tells someone to make one specific thing and have it done.

The shape to memorize

Vařit / uvařit is a model prefix-only pair: both halves share the stem and endings, and the perfective simply adds the empty prefix u-, which here contributes no meaning of its own — it only packages the cooking as finished. This is the cleanest, most common way Czech builds a perfective, the same template as dělat / udělat "do / get done." Learn vařit / uvařit and you have both a survival verb for every kitchen and a clean example of the simplest aspect-pair pattern.

Common Mistakes

Key Takeaways

• vařit = imperfective (cooking as a process or habit, in progress); uvařit = perfective (one finished meal).
• Imperfective vařím is a real present; perfective uvařím means "I will cook."
• vařit covers both cook (food) and boil (liquid): vařit polévku, voda vaří (literary vře).
• The cooked thing is a bare accusative (vařit oběd); add si to cook for yourself (uvařit si čaj).
• The pair is built by the empty prefix u- alone — the simplest, most common aspect-pair template, like dělat / udělat.