Roommate

Dust it off!
To tell someone to do something, du‑st off the sentence — in other words, take away the du and the ‑st!
Du trinkst kein Bier.
You drink no beer.​
Trink kein Bier!
Drink no beer!​
You’ll sometimes see an ‑e added to the du command (for example, Trink! and Trinke!). Don’t worry, the meaning is still the same.
Listen up, all of you!
If you’re telling a group of people to do something, just drop the ihr.
Ihr bleibt bei mir.
You all stay with me.
Bleibt bei mir!
Stay with me!​
Watch out!
If you use a stem vowel changing verb like lassen (ich lasse, du lässt, etc.) you don’t keep that ä when giving orders!
Lass das!
Leave it!​
If you want to tell someone to be good or not be silly, you’ll need these special forms:
du
you​
Sei!
(You) be!​
ihr
you all​
Seid!
(You all) be!​