aren't there adverbs of interrogative and purpose?

Interrogative adverbs are 'how, why, where and when'. They are used to ask questions.
For example:
How was the play?
When did it start?
Where was it staged?
Why was it staged?

Adverbs of purpose describe the reason or purpose of an action.
For example:
Shylock, therefore, became Antonio's enemy.
The plate is handcrafted, hence costly.