何〜ても・誰〜ても (no matter what, who)
no matter what / who / where / when
Question word + Verb て-form + も
Sign up free to review this point on a spaced schedule.
A question word plus ても means "no matter": 何を食べても太らない, "no matter what I eat, I don't put on weight".
The question word can be 何 (what), 誰 (who), どこ (where), いつ (when) or どう (how): 誰に聞いてもわからなかった, "no matter who I asked, nobody knew"; いつ来ても込んでいる, "whenever I come, it's crowded".
It's ても (N4) with a question word in front, so the verb takes the て-form plus も. The second half is the same result every time.
Compare たら, "if, when": 何を食べたら is "what should I eat", a real question. ても says the answer doesn't matter.
Examples
何を食べても太らない。
No matter what I eat, I don't put on weight.
誰に聞いても、答えがわからなかった。
No matter who I asked, nobody knew the answer.
いつ来ても、この店は込んでいる。
Whenever I come, this shop is crowded.
どこを探しても、鍵が見つからない。
No matter where I look, I can't find my keys.
どう説明しても、わかってもらえない。
However I explain it, they don't understand.