何でも details

anything, anyone, anywhere, any time — a question word plus でも takes in the whole set + write

nandemo kaku

anything, anyone, anywhere, any time — a question word plus でも takes in the whole set

meaning: write anything at all

彼かれは好すき嫌きらいがなくて、何でもなんでも食べるたべる。

kare wa sukikirai ga nakute, nandemo taberu.

He isn't fussy and eats anything at all. neutral

場所ばしょはどこでもいいよ。任まかせる。

basho wa dokodemo ii yo. makaseru.

Anywhere's fine by me — your call. casual

Examples

any at all — the speaker refuses to narrow the choice, and the predicate holds for every member of the set

彼かれは好すき嫌きらいがなくて、何なんでも食たべる。

kare wa sukikirai ga nakute, nandemotaberu.

He isn't fussy and eats anything at all. neutral

場所ばしょはどこでもいいよ。任まかせる。

basho wa dokodemo ii yo. makaseru.

Anywhere's fine by me — your call. casual

この資料しりょうは、誰だれでも自由じゆうに使つかえます。

kono shiryou wa, daredemo jiyuu ni tsukaemasu.

Anyone is free to use these materials. neutral

ご不明ふめいな点てんがございましたら、いつでもお問とい合あわせください。

go fumei na ten ga gozaimashitara, itsudemo o toiawase kudasai.

If anything is unclear, please get in touch at any time. formal

Sentence-initial 何なんでも is a different word altogether — 何なんでも、
彼かれは来月らいげつ辞やめるらしい means "from what I hear".

ても
ても needs a whole clause to concede (誰だれが読よんでも分わかる); a question word plus でも packs that same concession into one word and leaves a noun phrase you can mark with が or を — 誰だれでも分わかる, 何なんでも食たべる.

誰も〜ないpolarity
誰だれでも and bare 誰だれも split the same set by what follows — でも sweeps it with a positive predicate (誰だれでも分わかる, everyone does), while an unmarked or に-marked 誰だれも wants a negative one (誰だれも分わからない, nobody does).

どこか
One kana decides how much of the set you get — か opens a single member and refuses to name it (誰だれか来きた, somebody came), でも takes in every member at once (誰だれでも来こられる, anybody may come).