Final answer:
The part of speech that answers the questions of who, what, where, when, how and why is the adverb clause.
Step-by-step explanation:
The part of speech that answers the questions of who, what, where, when, how and why is the adverb clause.
An adverb clause is a group of words that functions as an adverb and provides answers to these questions. It typically begins with a subordinating conjunction such as 'when,' 'where,' 'how,' or 'why.'
For example:
'He went to the store when the rain stopped' - answers the question 'when'
'I found my keys where I left them' - answers the question 'where'