1.
what, what matter, what on earth
Used to ask or express surprise about what is happening. More formal or dramatic than simply なに.
何事かと思った。
I wondered what was going on.
外で大きな音がして、何事かと窓を開けた。
There was a loud noise outside, so I opened the window to see what was happening.
何事もなかったように振る舞った。
He acted as if nothing had happened.
2.
everything, anything, all matters
Used with も to mean 'everything' or 'anything,' often in the context of approaching all things with a certain attitude.
何事も経験だ。
Everything is an experience.
何事も最初が肝心だ。
In everything, the beginning is crucial.
何事にも全力で取り組む姿勢が大切だ。
The attitude of giving your all in everything is important.
何事 is a more formal and dramatic way of saying "what" (何). It also means "everything/anything" when paired with も.
SENSE 1 — WHAT (SURPRISE/ALARM):
- 何事かと思う: to wonder what is going on
- 何事だ: What's happening? / What is this?
- 何事もなかったように: as if nothing had happened (very common set phrase)
SENSE 2 — EVERYTHING/ANYTHING:
- 何事も経験だ: everything is an experience
- 何事も最初が肝心: in everything, the start is crucial
- 何事にも全力で: with full effort in everything
REGISTER:
More literary and elevated than plain 何. Conveys gravity, importance, or philosophical tone. Common in proverbs, speeches, and narrative writing.
WORD FORMATION:
何 (what) + 事 (matter, thing). The combination creates a weightier word than either part alone.