musieť / môcť (Likelihood)

Must and May for Likelihood

Level 4

Musieť and môcť can say how likely something is: Musí byť unavený (He must be tired), Môže pršať (It may rain). Context shows whether the verb is about likelihood or about duty and permission.

How It Works

How sure are you? From most to least likely:

  • Určite je doma. He is definitely at home.
  • Musí byť doma. He must be at home. (I am almost sure.)
  • Môže byť doma. He may be at home.
  • Nemusí byť doma. He might not be at home.
  • Nemôže byť doma. He can't be at home.

Guessing about the past. Slovak has no separate "must have" or "may have". Put the modal verb in the past and keep the infinitive: Musel zabudnúť. (He must have forgotten.) Muselo sa niečo stať. (Something must have happened.) Mohla zmeškať autobus. (She may have missed the bus.) The same words can also mean "had to" or "was able to", so context decides: Musel odísť can mean "He had to leave".

Softer with the conditional. Mohlo by pršať. (It could rain.) To by mohla byť pravda. (That could be true.) See The Conditional Mood.

Two different negatives. Nemôže says something is impossible: To nemôže byť pravda! Nemusí says it is not necessarily so: Nemusí to byť pravda. (It is not necessarily true.) Never use nesmie for likelihood; it means "is not allowed". See Don't Have To and Must Not.

Short answers. Môže byť. (Could be.) Words like asi and možno give the same range of certainty without a modal verb.

Examples (6)

  1. Musí byť doma, svieti sa tam.

    He must be at home; the light is on.

    Word by Word: He-must be at-home, it-shines there.

  2. Môže to byť pravda.

    It may be true.

    Word by Word: It-can that be truth.

  3. To nemôže byť pravda!

    That can't be true!

    Word by Word: That not-can be truth!

  4. Kľúče nemám, musel som ich nechať v kancelárii.

    I don't have my keys; I must have left them at the office.

    Word by Word: Keys not-I-have, I-had-to them leave in office.

    A guess about the past: the modal itself is in the past.

  5. Ešte neprišla, mohla zmeškať autobus.

    She hasn't arrived yet; she may have missed the bus.

    Word by Word: Still she-didn't-come, she-could miss bus.

  6. Nemusí to byť nič vážne.

    It doesn't have to be anything serious.

    Word by Word: Not-must it be nothing serious.

    Nemusí means "not necessarily", not "can't".

Common Mistakes

  • Trying to build "must have" with a present modal.

    Musí zabudol na stretnutie.
    Musel zabudnúť na stretnutie.

    For a guess about the past, put musieť in the past and keep the infinitive: musel zabudnúť (he must have forgotten).

  • Using nesmieť to say something is impossible.

    To nesmie byť on, je v Londýne.
    To nemôže byť on, je v Londýne.

    To nesmie byť on means that he is not allowed to be the one. To say "That can't be him", use nemôže.

  • Using nemusí to mean "can't be".

    Je v Londýne, takže tu nemusí byť.
    Je v Londýne, takže tu nemôže byť.

    Here the speaker wants to say that he can't possibly be here. Tu nemusí byť means he doesn't have to be here, or might not be here. Because he is in London, use nemôže.

How It Connects

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

musieť / môcť (Likelihood)Level 4Must and May for Likelihood

Learn This First

Before Must and May for Likelihood, learn Can and Must and Probably and Maybe. musieť and môcť also express likelihood. asi and možno express the same degrees of certainty.

Words in This Pattern

musieťnemôcť