Imperfective infinitive after phase verbs

Level 2

When you use verbs like začít (to start) or přestat (to stop), the following verb must be in the imperfective aspect.

How It Works

What are phase verbs?
Phase verbs express the beginning, end, or continuation of an action. The most common ones are začít/začínat (to start), přestat/přestávat (to stop), and zůstat/zůstávat (to remain, which is primarily restricted to verbs of position, posture, or visual fixation, such as sitting, standing, or staring/looking, but also includes states like mlčet - to remain silent, or bydlet - to continue living).

The Golden Rule:
A phase verb must connect directly to an imperfective infinitive. Unlike English, there is no connecting word like "to" between the verbs. This rule applies identically even when the phase verb is negated (e.g., nezačal, nepřestával). Note that some phase verbs are not limited to infinitives; they can also take noun objects, though the required case depends on the verb (e.g., začít can take a direct accusative object like Začal novou práci - He started a new job, or s + instrumental like Začal s tenisem - He started playing tennis, while přestat requires s + instrumental like Přestal s prací - He stopped working).

The Future Tense Trap:
When talking about the future, only the phase verb changes tense. The second verb remains a bare infinitive. Do not try to put both verbs in the future tense (e.g., never say začnu budu číst; the correct form is začnu číst - I will start reading).

Aspect Independence:
The phase verb itself can be perfective (začal - he started once) or imperfective (začínal - he was starting). However, regardless of the phase verb's aspect, the infinitive that follows it is always imperfective. It is a misconception that the aspects of the two verbs need to match.

Contrast with Modals:
Do not confuse this rule with aspect in infinitives after modal verbs. Modals like muset (must) or chtít (want) can take either aspect depending on your meaning. Phase verbs have no such flexibility; they strictly reject perfective infinitives.

The pokračovat Trap:
English speakers often try to translate "continue doing" as pokračovat + infinitive. This is strictly forbidden in Czech! To express continuing an action, you must either use pokračovat v + locative noun (e.g., pokračovat v práci - to continue working) or simply use the main verb with the adverb dál (e.g., pracoval dál - he kept working).

Stopping vs. Finishing:
If you want to say you "finished" doing something, do not use přestat. Instead, use a perfective verb with a completive prefix (e.g., dočíst - to finish reading). Přestal číst means "he stopped reading" (he put the book down, perhaps unfinished). Also, beware of the verb skončit (to finish). English speakers often incorrectly try to use skončit + infinitive (e.g., skončil jsem pracovat). This is incorrect in Czech! Instead, skončit requires the preposition s + instrumental case (e.g., skončil jsem s prací - I finished working), a standard noun object in the accusative (e.g., skončil práci), or it can be used intransitively (e.g., film skončil - the movie finished). Similarly, the verb dokončit (to complete/finish) cannot be paired with an infinitive; it strictly requires a noun object (e.g., dokončil projekt - he finished the project).

Examples (4)

  1. Začal jsem psát dopis.

    I started writing a letter.

    Word by Word: Started am write letter.

    The perfective phase verb 'začal' is followed by the imperfective infinitive 'psát'.

  2. Přestala kouřit před rokem.

    She quit smoking a year ago.

    Word by Word: Stopped smoke before year.

    The perfective phase verb 'přestala' is followed by the imperfective infinitive 'kouřit'.

  3. Najednou začalo pršet.

    Suddenly it started to rain.

    Word by Word: Suddenly started rain.

    Even in impersonal sentences about the weather, the rule applies: 'začalo' + imperfective 'pršet'.

  4. Zůstal stát venku.

    He remained standing outside.

    Word by Word: Remained stand outside.

    The phase verb 'zůstat' (to remain) requires an imperfective infinitive. Note that it is primarily used with verbs of physical position or visual fixation (like 'stát' - to stand, or 'ležet' - to lie), but also applies to certain states like 'mlčet' (to remain silent).

Common Mistakes

  • Using a perfective infinitive after a phase verb.

    Začal napsat dopis.
    Začal psát dopis.

    English speakers often use a perfective verb because the act of starting happened in the past and feels 'finished'. However, the completion belongs to the starting (začal), not the writing (psát). You can only start a process, so the infinitive must be imperfective.

  • Assuming the aspect of the infinitive must match the aspect of the phase verb.

    Přestal vykouřit.
    Přestal kouřit.

    It is a common misconception that if the phase verb is perfective, the infinitive should be perfective too. The phase verb's aspect is chosen freely based on context, but the infinitive complement remains strictly locked to the imperfective.

  • Using an infinitive after the verb 'pokračovat' (to continue).

    Pokračoval číst knihu.
    Pokračoval ve čtení knihy.

    Unlike English, the Czech verb 'pokračovat' cannot be followed by an infinitive. To say you 'continue doing' something, you must use 'pokračovat v' + a noun in the locative case (like 've čtení' - in reading), or use the main verb with the adverb 'dál' (e.g., 'četl dál' - he read further).

How It Connects

Tap a pattern to see what it builds on and what it leads to.

Imperfective infinitive after phase verbsLevel 2

Learn This First

To learn phase verbs, you first need to understand the concept of verbal aspect (perfective vs. imperfective) because phase verbs only pair with imperfective infinitives. Additionally, you should be familiar with the 'verb + infinitive' structure, which is commonly introduced through modal verbs.

Words in This Pattern

začítpřestatpřestávat