究竟 (exactly / on earth)
"Exactly what happened?"
- to go to the bottom of a…究竟 is the bookish twin of finally到底: "exactly / on earth / after all".
- to go to the bottom of a…究竟to happen发生(completed / change)了what什么？ = "what exactly happened?"
- Same job as finally到底, a touch more formal.
to go to the bottom of a…究竟 + Question
- to go to the bottom of a…究竟 sharpens a question, demanding the precise answer.
this这exactly究竟is是how怎么matter回事？
- this这to go to the bottom of a…究竟to be / is是what's the matter?怎么回事？ = "what exactly is going on?"
Practice
What exactly is going on? 这 ____ 是怎么回事?
究竟 + Question demands the precise answer: 这究竟是怎么回事?
to go to the bottom of a…究竟 vs finally到底
- Same meaning; finally到底 is more spoken, to go to the bottom of a…究竟 more written / formal.
Explore
Correct or broken?
究竟 is the formal 到底 — same pressing force, same rules.
Practice
How does 究竟 compare with 到底?
Both = “exactly / on earth”; 到底 spoken, 究竟 formal.
Practice
究竟 and 到底 have opposite meanings.
They mean the same; only the register differs.
Recap
Key idea
- to go to the bottom of a…究竟 + Question — "exactly / on earth …?": to go to the bottom of a…究竟to happen发生(completed / change)了what什么?
- Same as finally到底, slightly more formal / written
- Demands the precise answer
Read the full reference: HSK 4 grammar — Adverbs.