měl bych + Infinitive

Conditional Advice and Mild Obligation

Level 3

The pattern měl bych + infinitiv is the standard way to say "should" in Czech. It is used to give advice, make recommendations, or express a soft obligation based on personal opinion.

How It Works

1. Meaning and Nuance
Unlike muset (must/have to), which expresses strict necessity, měl bych is much softer. It conveys what would be good or advisable to do. It also differs from the present tense of mít (mám, máš + infinitive), which implies an external instruction or expectation (e.g., "I am supposed to").

2. Formation
You need three parts to build this pattern:

  • The past participle of mít, which must agree with the gender and number of the subject (e.g., a male speaker says měl bych, while a female speaker says měla bych): měl (masculine), měla (feminine), mělo (neuter), měli (masculine animate plural), měly (feminine and masculine inanimate plural), měla (neuter plural).
  • The conditional auxiliary: bych (I), bys (you), by (he/she/it), bychom (we), byste (you plural/formal), by (they). Note: In spoken Czech, you will often hear the colloquial form bysme instead of bychom, but you should stick to bychom in formal writing.
  • The infinitive of the action verb.

Because the auxiliary and participle already encode the person, gender, and number, personal pronouns (já, ty, my, etc.) are typically omitted. Using them sounds unnatural unless you want to emphasize the subject.

3. Negation and Reflexive Verbs
To form the negative, attach the prefix ne- to the past participle: neměl bych (I shouldn't). When using reflexive verbs, the 2nd person singular auxiliary bys fuses with the reflexive pronouns se or si to become by ses or by sis (e.g., Měl by ses omluvit.).

4. Word Order
The conditional auxiliary (bych, bys, by...) is a second-position clitic. It must occupy the second syntactic slot in the clause. If there are multiple clitics, the conditional auxiliary must be the first item in the clitic cluster. If měl is not the first word, the auxiliary detaches and jumps to the second position (e.g., To bys měl vědět.).

5. Time Reference
Despite using the past participle měl, this pattern refers to the present or future ("I should do it now/tomorrow"). To say "I should have done it" (past), Czech uses the past indicative: Měl jsem to udělat.

Examples (4)

  1. Měl bys jít k doktorovi, ten kašel zní hrozně.

    You should go to the doctor, that cough sounds awful.

    Word by Word: Should would-you go to doctor, that cough sounds terribly.

    Informal advice addressed to a male. Notice how 'měl' agrees with the masculine subject.

  2. Měla byste si odpočinout.

    You should rest.

    Word by Word: Should would-you yourself rest.

    Formal advice addressed to a female. 'Měla' is feminine singular, while 'byste' indicates formal address.

  3. Neměli bychom na to čekat do poslední chvíle.

    We shouldn't wait for it until the last minute.

    Word by Word: Not-should would-we for it wait until last minute.

    First-person plural negative. The negative prefix 'ne-' attaches to the participle 'měl'.

  4. Co bych měl udělat?

    What should I do?

    Word by Word: What would-I should do?

    A question asked by a male. Notice how the clitic 'bych' jumps to the second position, right after the question word 'Co'.

Common Mistakes

  • Omitting the participle 'měl/měla' and using only the conditional auxiliary.

    Já bych jít k doktorovi.
    Měl bych jít k doktorovi.

    English builds 'should' directly with the infinitive, but Czech requires the conditional form of the verb 'mít' (měl bych). Without 'měl', the sentence is grammatically incomplete.

  • Writing 'by jsi', 'by jsme', or 'by jste' as separate words.

    Měli by jsme to zkusit.
    Měli bychom to zkusit.

    The conditional auxiliaries are single words: 'bys', 'bychom', and 'byste'. Writing them as two words ('by jsi', 'by jsme', 'by jste') is a very common spelling error, even among native speakers, but it is strictly incorrect in standard Czech.

  • Assuming 'měl bych' means 'I should have' (past tense).

    Včera jsem měl bych tam jít.
    Včera jsem tam měl jít.

    Even though 'měl' is a past participle, 'měl bych + infinitiv' refers to present or future advice. To express past regrets ('I was supposed to / I should have'), use the past indicative of 'mít' (měl jsem + infinitiv).

How It Connects

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

měl bych + InfinitiveLevel 3Conditional Advice and Mild Obligation

Learn This First

To understand 'měl bych + infinitiv', you need to know how to form the past participle (l-participle) of the verb 'mít' and how to use the conditional auxiliary 'bych' (and its forms like 'bys', 'by', etc.). Understanding the placement of these clitics in a sentence is also essential.

Words in This Pattern

mít