The infinitive

 
The infinitive is the citation form of each verb. It is formed with the present tense stem and the ending -en or, more seldom, with the ending -n.

 

Examples
spiel-en
fahr-en
tanz-en
sprech-en
änder-n

 

Note: The infinitive ending -n is used in verbs sein and tun and when the verb stem ends in -el and -er.