Modal Verbs With Infinitives

Modal verbs modify another verb to express possibility, ability, or obligation. In Polish, the second verb usually remains in the infinitive, provided the subject of both verbs is the same.

1. Core Modal Verbs

• Umieć: Learned skill or knowledge (Umiem mówić po polsku - I know how to speak Polish).
• Potrafić: Ability or acquired skill, but unlike umieć, it also expresses physical capability or managing to do something (Potrafię wstrzymać oddech na minutę - I can hold my breath for a minute).
• Móc: Situational possibility or permission (Mogę wejść? - Can I come in?).
• Musieć: Necessity or obligation (Muszę pracować - I must work).
• Chcieć: Desire (Chcę pić - I want to drink). Note: If the subject of the desire is different from the subject of the action, you must use a żeby clause instead of an infinitive.
• Powinien: Recommendation or 'should'. This verb behaves like an adjective combined with the personal endings of the verb 'to be', conjugating for both gender and person (e.g., powinienem / powinnam = I should [male/female], powinieneś / powinnaś = you should [male/female], powinien / powinna = he/she should).
• Mieć: When followed by an infinitive, it means 'to be supposed to' (Mam to zrobić - I am supposed to do it).

2. Impersonal Modals
Polish frequently uses impersonal forms. Trzeba means 'one must' or 'it is necessary', można means 'one can' or 'it is possible', wolno means 'one is allowed', and warto means 'it is worth'. You might also see należy (one should / it is proper to). They are followed by an infinitive (e.g., Warto to zobaczyć - It is worth seeing). While some impersonal modals like wolno can take a Dative pronoun to specify who it applies to (e.g., Nie wolno mi - I am not allowed), others like trzeba and można generally do not in modern Polish. Instead, use personal verbs (like musisz) to specify the subject. To change the tense of these impersonal modals, add the 3rd-person neuter auxiliary było (past) or będzie (future) (e.g., trzeba było, można będzie).

3. The Infinitive and Aspect
While the infinitive often follows the modal, Polish word order is flexible. Short pronouns and reflexive clitics frequently separate them (e.g., Muszę to zrobić, Chcę się uczyć). Use an imperfective infinitive for habits or ongoing states, and a perfective infinitive for specific, one-time results.

4. Negation Nuances
Negating these verbs changes the meaning: nie muszę means "I don't have to" (optional). While nie mogę means "I cannot" (usually due to circumstantial inability, like being too busy), to express strict prohibition, use nie wolno.

Trzeba With a Needed Thing: Trzeba mi czasu (I need time) is a valid construction with dative mi and genitive czasu. Distinguish that noun construction from the ordinary personal-obligation wording Muszę pracować (I must work).

More Powinien Forms: Neuter singular is powinno: Dziecko powinno odpocząć (The child should rest). Masculine-personal plural forms are powinniśmy, powinniście, powinni; other plural forms are powinnyśmy, powinnyście, powinny. For example, Dziewczyny powinny odpocząć (The girls should rest).