居然 / 竟然jūrán / jìngrán

Adverbs 居然 / 竟然 (jūrán / jìngrán): Unexpectedly / To one's surprise

Meaning: Unexpectedly, to one's surprise, actually

Pattern

Both 居然 and 竟然 mean "unexpectedly / to one's surprise / hard to believe that...", expressing astonishment at something contrary to common sense or expectations.
They are placed after the subject and before the verb, adjective, or modal verb, and are often reinforced by 没想到 at the start of the sentence (没想到他竟然这么聪明).
Distinguish 居然/竟然 (speaker's surprise at an improbable fact) from 突然 ("suddenly", describing a rapid change in situation).

1
他居然把这件事忘了。
Tā jūrán bǎ zhè jiàn shì wàng le.
He unexpectedly forgot about this matter!
2
没想到他竟然这么聪明。
Méi xiǎngdào tā jìngrán zhème cōngmíng.
I didn't expect that he would be so smart.
3
这么简单的题，他居然不会做。
Zhème jiǎndān de tí, tā jūrán bù huì zuò.
Such a simple question, and he actually doesn't know how to do it!

•Placed after the subject and before the predicate; distinguish from 突然 ("suddenly") and 当然 ("of course").

⚠️ Common Mistakes:

•Confusing 居然/竟然 ("unexpectedly") with 突然 ("suddenly").

•Placing 居然 or 竟然 after the main verb instead of before the predicate.

Combine Vocabulary, Grammar, Reading Practice, Listening, Hanzi Writing, and Mock Exams at HSK 4 to master all skills together.