yes
No, "enveloped" is not an action verb; it is the past tense of the verb "envelop," which means to completely cover or surround something. In a sentence, it describes an action that has already taken place, but it functions as a verb rather than an action verb in isolation.
Yes, the word 'covered' is the past participle, past tense of the verb to 'cover', an action verb.
It is an action verb.
began is an action verb, not a linking verb.
action verb because you did this action (sent)
what follows a linking or action verb
It is an action verb.
Action verb
Action verb
action verb
An action verb
The verb stay is an action verb.