Structure:

究竟+question

Meaning:

When someone asks you “what on earth are you doing?”, “on earth” is used by the speaker to intensify the question. 究竟 (jiūjìng) can be used in the same way.

Examples:

1. 这次 欧洲杯 的 冠军究竟 是 哪个 队？广告 之后 就 会 知道！

    zhècì ōuzhōubēi de ɡuànjūnjiūjìnɡ shì nǎɡè duì？ɡuǎnɡɡào zhīhòu jiù huì zhīdào

    Which team won the European Cup in the end? Find out after these commercials!

2. 你 究竟 喜 不 喜欢 我？

    nǐ jiūjìnɡ xǐ bú xǐhuɑn wǒ？

    So, do you like me or not?

3. 你 究竟 看 到 我 了 没有？

    nǐ jiūjìnɡ kàn dào wǒ le méiyǒu？

    Did you see me or not?!

4. 究竟 吃 什么？每天 都 得 想 这个 问题！

    jiūjìnɡ chī shénme？měitiān dōu dé xiǎnɡ zhèɡe wèntí

    What on earth do you want to eat? We have this problem every day!