N5
なにか・なにも
Something, Nothing, Anything, Not anything, Some kind of, Not any kind of
冷蔵庫の中には何もないです。
There is nothing inside the refrigerator.
Explanation
「なにか・なにも」 has 2 uses
1Something
何か means something, without saying what: 「何か食べますか」 (Will you have something to eat?).
なにか食べる？
Do you want to eat something?
何か食べますか？
Do you want to eat something?
2Nothing
何も always takes a negative and means nothing at all: 「何も食べません」 (I will not eat anything).
冷蔵庫の中には何もないです。
There is nothing inside the refrigerator.
いいえ、なにもしていませんよ。
No, you haven't done anything.