Modal verbs are very useful in German. They help you talk about what you have to do, want to do or are allowed to do and can be used in the present, past and conditional tenses.
Modal verbs are not conjugated in the same way as other verbs in the present tense.
Whereas in the regular present tense, each person in the singular forms have different endings, the first person singular form (ich) and the third person singular form (er, sie, es, man) in modal verbs are the same and have no endings. This applies to all modal verbs in the present tense, eg