budu muset / budu moci

Future with Modal Verbs

Level 3

To say "I will have to" or "I will be able to", Czech uses the future auxiliary budu followed by the infinitive of the modal verb (muset or moci/moct), and then the infinitive of the main action.

How It Works

To express future necessity or ability, Czech uses a three-part structure:

Future of být (budu, budeš...) + Modal Infinitive (muset, moci/moct) + Main Verb Infinitive

1. Choosing the right infinitive for "can"
The verb "to be able to" has two accepted infinitive forms. Moci is formal and literary. In everyday spoken Czech and casual writing, native speakers overwhelmingly prefer the simplified infinitive moct (e.g., budu moct). The verb muset has only one form. Stylistic tip: Native speakers often bypass budu moct in casual speech by simply using the perfective future of the main verb to imply ability (e.g., saying Pomůžu ti instead of Budu ti moct pomoct).

2. Present vs. Future Modals
If an obligation is already a set plan, Czechs often use the present tense (Zítra musím pracovat = I have to work tomorrow). However, budu muset is often used when the obligation will arise later as a consequence of something else (Když to rozbiješ, budeš to muset zaplatit = If you break it, you will have to pay for it), or simply to emphasize the future timeframe of an existing plan.

3. The "Perfective Future" Myth and Aspect
Learners are often taught never to use budu with a perfective verb. This rule means budu cannot attach directly to a perfective verb. Because muset and moci are imperfective, the construction budu + modal + perfective main verb (like budu muset napsat) is perfectly grammatical and highly common. The choice of the main verb's aspect depends on your focus: use an imperfective verb to focus on the process or duration, and a perfective verb to focus on the completed result.

4. Word Order
Remember that Czech clitics (like se/si or short pronouns like ho/to) must stay in the second position of the clause, not at the end of the verb cluster (Budu se muset učit, not Budu muset učit se). If you start the sentence with a subject pronoun or another word, the clitic still takes the second position, pushing the auxiliary verb to the third position (e.g., Já se budu muset učit, not Já budu se muset učit).

5. Negation
To negate this structure, attach the negative prefix ne- to the auxiliary verb být, not the modal verb (e.g., nebudu muset = I won't have to, nebudu moct = I won't be able to). Crucial warning: Nebudu muset NEVER means "I must not" (prohibition). It only means a lack of obligation ("I won't have to"). To express a future prohibition, you must use the verb smět (to be allowed): nebudu smět = I won't be allowed to / I must not.

Examples (5)

  1. Budeme muset počkat na příští vlak.

    We will have to wait for the next train.

    Word by Word: We will have to wait for next train.

    A standard future obligation. Notice that the main verb 'počkat' is perfective, which is perfectly fine after 'budeme muset'.

  2. Až se uzdravím, budu zase moct běhat.

    Once I get better, I'll be able to run again.

    Word by Word: When myself I heal, I will again be able to run.

    Uses the colloquial and highly common infinitive 'moct'. The ability to run is contingent on a future event (getting better).

  3. Budeš to muset udělat znovu.

    You will have to do it again.

    Word by Word: You will it have to do again.

    Notice the clitic 'to' placed in the second position, before the modal verb cluster.

  4. Zítra nebudu moct přijít na schůzku.

    I won't be able to come to the meeting tomorrow.

    Word by Word: Tomorrow not I will be able to come to meeting.

    To negate the future modal, the negative prefix ne- attaches to the auxiliary verb (nebudu), not the modal.

  5. Když to rozbiješ, budeš to muset zaplatit.

    If you break it, you will have to pay for it.

    Word by Word: If it you break, you will it have to pay.

    A classic example of a contingent future obligation. The obligation to pay only arises if the item is broken.

Common Mistakes

  • Placing clitics at the end of the verb cluster.

    Budu muset učit se.
    Budu se muset učit.

    Czech clitics (like 'se', 'si', 'ho', 'to') must occupy the second position in the clause. They should not be pushed to the end of a long verb cluster.

  • Conjugating both the auxiliary and the modal verb.

    Budu musím pracovat.
    Budu muset pracovat.

    Only the auxiliary verb 'být' (budu, budeš...) is conjugated. The modal verb must remain in the infinitive form (muset, moci/moct).

  • Using the imperfective 'psát' when you mean a finished result.

    Different MeaningBudu muset psát ten e-mail.
    Budu muset napsat ten e-mail.

    'Budu muset psát ten e-mail' is a good sentence, but it means 'I will have to work on writing the email' (the process). To say you will have to write it and finish it, use the perfective 'napsat' after 'muset'. Only 'budu' cannot be followed directly by a perfective verb; after 'muset' it is fine.

How It Connects

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

budu muset / budu mociLevel 3Future with Modal Verbs

Learn This First

To form the future of modal verbs, you need to combine the future auxiliary 'budu' with the infinitive of the modal verb. Therefore, you must already know how to conjugate 'být' in the future and be familiar with the modal verbs 'muset' and 'moci' themselves.

Words in This Pattern

musetmoci