- No matter where you go, I will follow you.
After no matter, we use a present tense with a future meaning.
- You will be welcome no matter when you come.
No matter who and whoever
The conjunctions no matter who/what etc., are used rather like whoever, whatever etc.
- No matter what you say, I won’t believe you. (= Whatever you say, I won’t believe you.)
- Phone me when you arrive, no matter how late it is. (= Phone me when you arrive, however late it is.)