居然【jūrán】

居然 marks something the speaker finds hard to believe. It goes after the subject and before the verb, like 竟然, and means the same. 居然 is the more spoken of the two and often carries more feeling – delight, or indignation.

It often pairs with 连…都 or with a number that seems too large or too small.

居然 or 果然

The two look alike and mean opposite things. 居然 is "against all expectation"; 果然 is "just as expected".

• × 我猜他会迟到，他居然迟到了 → 我猜他会迟到，他果然迟到了

居然 or 反而

居然 only reacts to a surprise. 反而 says the result went the opposite way from what the first clause should have caused.