An IMperative (eye-em-pear-ative) is a sentence in an online conversation that is generally harmless except for when punctuated. This can lead to the recipient feeling the sender is issuing an imperative, often inappropriately, and respond harshly. Often observed in conversations between an illiterate douchebag and an English major.
2:53 Bob: man im so wasted
2:53 Bob: i think i need to do
2:53 Bob: my hw
2:54 Susie: Fine - go do your homework.
4:05 Bob: hey
4:05 Bob: FUck Off.
16:13 Bob: You IMperative loving whore