Interested in Language
This comes from my daughter's work at school- she was asked to form questions using "where".
1.I am going to the market.
"Where are you going?" or "Where are you going to?"
2. Mother went for shopping.
"Where did mother go?" or "Where did mother go to?"
Or are both questions correct?
Afterthought: there's also a semi-archaic single word that means 'where to' - whither. It's sometimes used currently in very formal contexts: 'And so, my friends, we must ask ourselves "Whither capitalism?"' [= "where is it going to?"] It's probably not wise to use it yourself, but you may meet it now and then.
PS It's sometimes also used in self-consciously polite contexts - often humorous.
A: I'm going out.
B: Whither, pray? [English speakers used to pepper their speech with 'pray' not unlike the Italian equivalent prego (equivalent, that is, in terms of the basic meaning: 'I pray')]