For the purposes of learning and teaching Polish verbs, very often all verbs are separated into one of four groups, or classes, where the rules for the endings for first person, second person and third person, in their plural and singular usages are defined. As with all grammar, these rules are by no means hard and fast, and there are a whole host of sub-classes and exceptions for verbs in each class, but for now it’s not worth worrying about these, because learning rules is often not as effective as picking these anomalies up as you go along (especially in Polish). It is worth getting acquainted with the endings common to each class though, as this will allow you to use verbs more confidently for a variety of sentence subjects (I, you, he, she, they, we).
Verb endings are a source of great frustration for many learners of Polish. It’s difficult to get used to asking a question with one ending and receiving an answer with another, or indeed, doing the reverse and changing your ending to reflect a new subject. For example, if I asked someone if they have onion – ‘masz cebulę?’ - they may reply to me using the same verb (‘to have’), but with a different ending - ‘tak, mam cebulę’ . These verb classes make it easier for students of Polish to recognise who someone is addressing or referring to when they use a verb.
Class 1 Polish Verbs
The endings for class one verbs are: -ę (first person singular), -esz (second person singular), -e (third person singular), -emy (first person plural), -ecie (second person plural), -ą (third person plural).
Here is an example of a class 1 verb with its conjugations: [infinitive] móc (to be able to), mogę (I can), możesz (you can), on/ona może (he/she can), możemy (we can), możecie (you [plural] can), oni/one mogą (they can).
Here there is often a change in the stem of the verb between the first person singular and the other forms, remember that if this is the case, the third person plural will always take the same stem form as the first person singular ( mogę/ mogą).
Class 2 Polish Verbs
The endings for class one verbs are: -ę (first person singular), -y/isz (second person singular), -y/i (third person singular), -y/imy (first person plural), -y/icie (second person plural), -ą (third person plural).
Here is an example of a class 2 verb, with conjugations: [infinitive] lubić (to like), lubię (I like), lubisz (you like), on/ona lubi (he/she likes), lubimy (we like), lubicie (you [plural] like), oni/one lubią (they like).
Class 3 Polish Verbs
The endings for class 3 verbs are: -am (first person singular), -asz (second person singular), -a (third person singular), -amy (first person plural), -acie (second person plural), -ają (third person plural).
Here is an example we saw earlier of a class 3 verb, with conjugations: [infinitive] mieć (to have), mam (I have), masz (you have), on/ona ma (he/she has), mamy (we have), macie (you [plural] have), oni/one mają (they have).
Class 4 Polish Verbs
Class 4 verbs are the rarest type and can really be seen as more of a sub-class of class three verbs, as the only difference is the vowel (-a/-e) in the ending. There are no subclasses for this group of verbs.
The endings for class 4 verbs are: -em (first person singular), -esz (second person singular), -e (third person singular), -emy (first person plural), -ecie (second person plural), -ają (third person plural).
Here is an example of a class 4 verb, with all the conjugations in Polish: [infinitive] mówić (to say), mówię (I say), mówisz (you say), on/ona mówi (he/she says), mówimy (we say), mówicie (you [plural] say), oni/one mówią (they say).
Thank you for the correction, Marcel Jagiełło :)