What are interrogative adverbs? They are; why, where, when, and how. We use these words/interrogative adverbs to ask questions. When we use these adverbs to make questions, we must invert the subject with the auxiliary verb. So; ‘why can you’ and NOT ‘why you can’.
‘Why’; we use ‘why’ to acquire a reason for something;
Why are you late today?
Why does David always ask just boring questions?
Why can’t we go to the beach this Saturday dad?
Note that, in all these examples the order is ‘interrogative adverb-auxiliary verb-subject’, as is the correct order for asking questions regardless of the adverb.
‘Where’; We use the interrogative adverb ‘where’ to talk ask about a place;
Where does Gemma live?
Where do we have to go tonight?
Where is the shop that you spoke to me about?
When‘; we use the interrogative adverb ‘when’ in reference to time.
When must we leave home?
When should they advise us of the problem?
When can I see you next?
‘How‘; we use the interrogative adverb ‘how’ to talk about the manner, degree, time, amount, or quantity in which something is done.
How did you know what he was talking about?
How can you show me the directions?
How does Jeremy know about our secret?
How much electricity de he use up?
How many drinks would you like?
In all the above examples we have examples of ‘how’ with; manner, degree, time, amount and quantity.