: Adverbs describes an action or state of being.

before action verbs [subject adverb verb]
write, hit, make, drive, move, wash, drop, etc.
The movers quickly moved our stuff.
The car slowly rolled into the intersection.
Stacy clearly made her point.
after be verbs [subject verb adverb]
is, am, are, was, were
You are clearly unhappy.
I am almost finished.
He is very angry.
sometimes and usually can be moved around Sometimes, the offices are open late.
The offices are open late, sometimes.
The offices are sometimes open late.
Usually, this device detects all movement.
This device detects all movement, usually.
This device usually detects all movement.