No. Simple is an adjective. The adverb form is "simply."
Adverb
Simply is an adverb (in a simple way, or literally).
Simplement
An adverb
Simply.
"Was copying " doesn't contain an adverb, it is only a verb (or simple predicate).
No. Often is an adverb.
Both?
A verb in the simple past.
The adverb is invisibly. Many -LE adjectives can form the adverb by changng the final E to Y (able, ably / simple,simply).
It is. This is a sample of a simple predicate. There is no predicate noun, adjective or adverb.