There are four classes of Polish verbs and once you’ve learnt the endings below, you’ll be able to reliably conjugate most of them in the present tense. As always, these are general rules to which there are some exceptions (such as the irregular verb być, which we’ve already written a blog post about) but most verbs will fit neatly into these rules. We’ll be covering each in more detail on our language blog soon.
If you’re interested in a book which has all the most common verbs, fully conjugated in every tense with example sentences, you should also check out Klara Janecki’s brilliant 301 Polish Verbs.
You can download the tables below as a handy PDF 
Class 1 verbs include: podróżować (to travel), pić (to drink), pisać (to write), interesować się (to be interested in), kupować (to buy), móc (to be able to), chcieć (to want)
Class 2 verbs include: robić (to do), mówić (to speak), lubić (to like), musieć (to have to), spać (to sleep), bawić się (to have fun)
Class 3 verbs include: mieć (to have), kochać (to love), czekać (to wait), śpiewać (to sing), pytać (to ask), biegać (to run), grać (to play), pływać (to swim), czytać (to read)
Class 4 verbs include: rozumieć (to understand), jeść (to eat), wiedzieć (to know), powiedzieć (to say)