fast
The German word 'schnell' is used to describe something that is quick or rapid. It can be used to describe speed in general, or it can be used to describe the speed of a specific action or event. For example, you might say 'Das Auto fährt schnell' to describe a car that is moving quickly.
Drive fast, we are late!
This sentence is in the imperative mode, giving a command to 'drive fast' due to the fact that 'we are late'. 'Schnell' is used here to convey the urgency and speed needed.
He can run very fast.
In this sentence, 'schnell' is used as an adverb to describe the verb 'laufen' (to run). It means that the subject of the sentence ('er' or 'he') is capable of running very fast.
Please do that quickly.
This is a polite request, using 'schnell' to indicate the desired speed of completion. 'Machen Sie das bitte schnell' is a way to politely ask someone to do something quickly.