Slovesný vid – základy

Most Czech verbs come in pairs. Both halves mean the same action, but one presents it as a process or a habit (the imperfective) and the other as a single, finished whole (the perfective). Psal jsem dopis - I was writing a letter, I spent time on it. Napsal jsem dopis - I wrote the letter, it is done.

Common pairs

Most perfectives are made with a prefix, but which prefix is not predictable: u-, na-, pře-, vy-, za- all appear. A few pairs change the stem instead (kupovat - koupit). Learn every new verb with its partner, as one vocabulary item.

English gives you half a clue

English was writing versus wrote feels similar, and it helps at first: I was writing is always imperfective. But English wrote can be either. I wrote to her every week is a habit, so Czech says psal jsem; I wrote the email this morning is one finished act, so napsal jsem. The question to ask is not "-ing or not?" but "Is this one completed whole?"

• Celý večer jsem četl. Nakonec jsem přečetl celou knihu. - I read all evening. In the end I finished the whole book.
• Každé ráno piju kávu. Dnes jsem vypil dvě. - Every morning I drink coffee. Today I drank two.
• Četl jsi Švejka? - Have you ever read Švejk? Asking about the experience, not the last page, takes the imperfective.

Words like každý den, často and celý večer pull towards the imperfective; už (already), nakonec (in the end) and a definite quantity (dvě kávy, celou knihu) pull towards the perfective.

A perfective has no "now"

Because a perfective is a finished whole, it cannot describe something in progress. Its present-tense forms mean the future: Zaplatím kartou - "I'll pay by card". In a pub you call for the bill with Zaplatím, prosím or the fixed phrase Platit, prosím!, and the waiter may ask Dohromady, nebo zvlášť? - together or separately?

Do not read the prefix as English re-: přečíst means "read through to the end", not "re-read". To read something again is přečíst znovu.