Formation of the imperative

The imperative of irregular verbs is formed, in the singular number, by deleting the personal pronoun du and the ending -st of the second person singular of the present tense indicative. When the verb stem vowel takes an Umlaut (ä / äu / ö) , the Umlaut is omitted.

* Verbs that change their stem vowel from "i to ie" in the present tense, always form the imperative without the suffix "e"  (exception: sehen).