I haven't gotten that far yet XD I usually write out new verbs I learn in the infinitive... but I guess I have enough patience to wait until I unlock the Infinitives skill ;)
I wouldn't be able to learn verbs without starting from their infinive form. So I searched them by myself on the internet. In the case of "bojíš se" that was a difficult one (it has only the first letter in common), i.e. bát se.