German Imperative
More of a mood than a verb tense, the imperative is used when giving a command.
Examples:
Call me tomorrow! - Ruf (formal: rufen Sie) mich morgen an!
Give me the book! - Gib (formal: geben Sie) mir das Buch!
Give them the money! - Gib (formal: geben Sie) ihnen das Geld!
You can also tell someone to sit by simply stating Sitz!. Komm! is the imperative form of kommen meaning Come! and Spiel! is the imperative form of spielen meaning Play!