Adverbs are, of course adverbials, but not all adverbials are adverbs.
Match the term in italics to the definition.
He left last August.
He left by bus.
He left to get his train.
He left when he saw me.
He left earlier.
He left sobbing loudly.
He left slowly.
He left because he need to catch a train.
He left at six o'clock.
He left through that door.
adverbial - infinitive of purpose
adverbial - non-finite (participial) clause
adverb - time
adverbial prepositional place phrase
adverbial - noun time phrase
adverbial clause - reason
adverbial - prepositional manner phrase
adverbial - prepositional time phrase
adverbial - time clause
adverb - manner