Student or Learner
is rigth to say Has he used sandpaper?
I would like you to understand a few things about our forum.
1. Post a question only ONCE. When you post the same question many times, it wastes your time and it wastes our time. People think they are helping you, and it turns out you have already received the right answer.
2. Give your threads titles that mean something. Don't use "hi" or "help." Use titles like "used/have used" or "present perfect question."
3. Start a new thread when you have a question, instead of posting on someone else's thread. *IF* the original poster has already received an answer, and *IF* the thread is recent and still active, and *IF* your question is very similar, you can add on, but it's best to just start a new thread.
If you follow those guidelines, people will be happy to help you undertand English better.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.