이제 와서 후회해 봤자 소용없어

The line, explained

Some lines in K-dramas are meant to sting. Today's comes at the moment a character who caused great harm finally says they are sorry, and the person they wronged is no longer interested. The grammar that delivers the blow is -아/어 봤자, 'even if you try, it's useless'. It is common in everyday Korean too, for anything from pointless arguments to bargain shopping, but in this scene it is as final as a door closing.

이제 와서 is a set phrase worth learning whole. 이제 means 'now', and 와서 is 오다, 'to come', with -아서, 'having come'. Together they mean 'now that it has come to this', 'after all this time'. It almost always signals that something is too late: 이제 와서 뭐 해? (what's the point now?). By itself it already carries reproach, and it prepares the listener for a dismissive ending.

후회해 is from 후회하다, 'to regret', a 하다 verb, so it becomes 후회해 before the ending. 봤자 is the clever part. It comes from -아/어 보다, the 'try doing' construction, plus -았/었자, an old ending meaning roughly 'even granting that'. So 후회해 봤자 is literally 'even granting that you tried regretting'. The ㅆ before ㅈ is written as t in romanisation, giving bwat-ja, and it sounds sharp and clipped when said in anger.

소용없어 is 소용, 'use, purpose', plus 없다, 'there is none'. It is a compact way to say 'it's pointless, it won't help'. -아/어 봤자 almost always pairs with a deflating second half like this: 소용없어, 똑같아 (it's the same), 뭐 해? (what's the point?), or a negative future such as 안 바뀔 거야 (it won't change). The shape is fixed: any effort in the first half, futility in the second.

Swap the effort and the coldness stays: 이제 와서 울어 봤자 소용없어 (crying now won't help), 이제 와서 빌어 봤자 소용없어 (begging now won't help), 이제 와서 사과해 봤자 소용없어 (apologising now won't help). Outside dramas, the pattern has a gentler second use, 'at most': 비싸 봤자 만 원이야 means 'it'll cost ten thousand won at the most'. Same ending, same idea of a ceiling, just aimed at prices instead of people.