네가 날 잊을까 봐 겁이 나

The line, explained

This is the verse before the chorus, the quiet admission. Not 'I love you' but 'I'm scared you'll forget me', which in a love song amounts to the same thing. The ending that does it is -(으)ㄹ까 봐, and once you know it you will hear it everywhere: in lyrics, in texts from a worried parent, in the excuse for bringing an umbrella on a sunny day. It is the grammar of 'just in case', and of caring too much.

네가 is 'you' as the subject. 네 is you, 가 is the subject marker, and because 네가 and 내가 (I) sound nearly identical, Koreans say 니가 out loud while still writing 네가. 날 is 나를, me, as the object, squeezed into one syllable. So the first two words set the stage completely: you, me, and whatever the verb is about to do between us. In this song, what it does is forget.

잊을까 봐 is the pattern. 잊다 is to forget; the stem 잊 ends in a consonant so it takes -을까 봐. The ending is built from two pieces you may already know. -(으)ㄹ까 is the wondering form, 'might it…?', and 보다 is to see, here in its casual form 봐. Put together they mean 'seeing that it might happen', which Korean uses for 'afraid that…' or 'in case…'. 네가 날 잊을까 봐 is 'afraid you might forget me'.

What follows -(으)ㄹ까 봐 is either a feeling or a precaution. Here it is a feeling: 겁이 나. 겁 is fear, 이 marks it as the subject, and 나다 means to arise or come out; 겁이 나다 is literally 'fear arises', the natural way to say 'I get scared'. The precaution version is just as common in daily life: 비 올까 봐 우산 가져왔어, I brought an umbrella in case it rains; 늦을까 봐 뛰어왔어, I ran here in case I was late.

Rhythm matters here. ne-ga nal i-jeul-kka bwa is the worry, rising slightly, and geo-bi na is the admission, falling. Try the frame with other fears: 네가 날 떠날까 봐 겁이 나, I'm scared you'll leave me; 네가 날 미워할까 봐 겁이 나, I'm scared you'll hate me. Each one says the same thing underneath: you matter enough to frighten me, and I wanted you to know.