Modalverben: moct, muset, chtít

Modal verbs are the Czech can, must, want, may. Like English modals they take a bare infinitive with no "to": Musím jít - I must go. Unlike English modals they conjugate like any other verb, and English can splits into three Czech verbs.

The forms

Můžu is what people say; mohu is the same word in formal writing.

Three Czech verbs for "can"

• umět - a skill you have learned: Umíš lyžovat? - Can you ski? With languages it needs no verb at all: Umím trochu česky.
• moct - nothing stops you, it is possible: Můžeš zítra přijít? - Can you come tomorrow? Na Sněžku můžeme jet lanovkou. - We can take the cable car up Sněžka.
• smět - you are allowed to: Smím dál? - May I come in? Tady nesmíte parkovat. - You can't park here.

The common mistake is to say *Můžu plavat for "I can swim". To a Czech that sounds as if the pool has just reopened. A skill is Umím plavat.

Mustn't and don't have to

Here English helps you. You already know that "you mustn't" and "you don't have to" mean different things. Czech draws the same line: nesmíš = you mustn't, nemusíš = you don't have to. Nemusíte platit, je to zdarma - You don't have to pay, it's free. The slip to avoid is translating "must not" word for word as *nemusíš, which gives permission instead of forbidding.

"Have to" is not mít

English builds obligation with have; Czech does not. "I have to go" is Musím jít. Mám jít? means "Am I supposed to go? / Shall I go?" - Mám zavolat taxi? "Shall I call a taxi?" With a direction, Czech often leaves the verb of motion out entirely: Musím do práce - I have to go to work.

And for "I'd like", the polite shop and café form, use chtěl bych (a man) or chtěla bych (a woman): Chtěla bych dvě vstupenky, prosím.