An adverbial can be an adverb:
句子的状语可以是一个副词

He spoke angrily.

They live here.

We will be back soon.

or an adverb with a quantifier:
或者一个用数量词修饰的副词

He spoke really angrily.

They live just here.

We will go quite soon.

We will go as soon as possible.

or a phrase with a preposition:
或者是一个介词短语:

He spoke in an angry voice.

They live in London.

We will go in a few minutes.