To understand an adverb clause let’s break it down. First, and adverb tells ‘how’, ‘when’ or ‘where’ and defines verbs or adjectives. A clause is a group of words that has to have a subject and a predicate. Therefore, an adverb clause would be a group of words that define a verb or adjective and tells ‘how’, ‘when’ or ‘where’. For example, look at the sentence ‘Tammy saw John.’ We can add an adverb clause, ‘when she was at the store’, to tell when exactly Tammy saw John. Adverb clauses can not stand alone, even though they have a subject and predicate, because they contain a linking word. In our example ‘when’ is the linking word.