Modal verbs

Modal verbs: können and müssen

The verbs können and müssen are modal verbs. They usually occur in a sentence with a second verb. The modal verb describes the relationship of the subject to the action, which is then expressed by the second verb.  

Factual description of an action:
Ich stehe auf.

Modal verb können: Description of a possibility or ability:
Ich kann aufstehen. (I am not seriously ill or injured. I am in a position to get up.)

Modal verb müssen: Description of a necessity:
Ich muss aufstehen. (I have an appointment or have to go to work. I am compelled to get up.)


Conjugation of modal verbs

Modal verbs are conjugated differently from "normal" verbs:

  • Modal verbs often have a different vowel in the singular than in the plural.
  • The form of the first- and third-person singular is the same. The verb has no ending.  

Example: müssen

1st person ich muss
2nd person du musst
3rd person er/sie/es muss
1st person wir müssen
2nd person ihr müsst
3rd person sie müssen
Formal (singular and plural) Sie müssen


Modal verbs in a sentence

  • In a simple statement in the present, the modal verb comes in second position in its conjugated form.
  • The second verb comes at the end of the sentence in the infinitive, i.e., this verb is not conjugated. 


Subject and modal verb   2nd verb (infinitive)
Ich muss morgen  arbeiten.
Du musst morgen  arbeiten.
Er muss morgen  arbeiten.
Wir müssen morgen  arbeiten.
Ihr müsst morgen  arbeiten.
Sie müssen morgen  arbeiten.


The sentence parts can be placed in a different order. However, the position of the modal verb and infinitive does not change: Morgen muss ich arbeiten.

Grammatical terms in German:

das Modalverb: Modal verbs are verbs that usually relate to a second verb, defining it more precisely. They make clear, for example, whether something is possible or necessary. In a sentence in the present tense, the modal verb is conjugated, while the second verb is used in the infinitive. 

der Infinitiv: The infinitive is the basic form of the verb that is not conjugated. This is the form of the verb that you usually find in vocabulary lists or in the dictionary. German verbs usually end in -(e)n  in the infinitive.