ABSTRACT
This chapter focuses on specific difficulties which arise mainly because of unexpected variation and outlines the specifics in regular/non-regular verbs and separable verbs, in reflexive verbs and modal verbs. It shows particular features of the auxiliary verbs 'haben' and 'sein'. Learners should know the basics of German verb forms: the verb endings and the formation of the tenses. Regular verbs are also sometimes called 'weak verbs'. In the present tense, there are four different endings indicating person in German which are added to the stem of the verb: -e, -st, -t, -en. The stem is the part of the verb with the infinitive ending taken off. The auxiliary verbs 'haben', 'sein', 'werden', and two other verbs, 'wissen' and 'tun', also belong in the group of 'non-regular' verbs. A number of non-regular verbs with the stem vowel '-e' change this to '-i' or '-ie' in the second and third persons singular.
