What to how to where to
In English, question words are pronouns. In questions, they're called "interrogative pronouns", but at other times they act like normal pronouns. Here are some examples of the question word + infinitive pattern.
- Please show me how to write it.
- I don't know how to do it.
- Tell me when to start.
- He knows where to go.
There are similar patterns involving question words as pronouns, such as the following.
- I don't know what time it is.
- I wonder why he plays baseball.