What are gold and copper used for?

This question is a little bit confusing in terms of what question category it belongs to. However, if the category is correct and the question is finding the incorrect word, then the answer would be the word “user”. The correct form of question should be “What are gold and copper used for?”, because it is inappropriate to ask a question about what a person is for.

If the question is asking about what a particular job (gold and copper user) does, then the question should be “What does a gold and copper user do?” On the other hand, if the category that the question belongs to is incorrect and the word “used” replaces the word “user” then the answer is that gold and copper are used for many things such as components for electrical devices, computers, and other stuff.