na jeol dae po gi a[a]n hae yo/I will never give up (on you)
나 절 대 포 기 안 해 요
vocabulary: na-I 나/ jeol da-never 절대/ po gi-giving up 포기/ a[a]n hae yo-don't 안해요
When the subject is NA[a], ending with YO is a little awkard. It wll be better to end the sensence without YO like "na jeol dae po gi an hae". This is the way to say " I will not give up" informally telling friends or people who are younger than you.
If you'd like to say with YO which is a formal way, you need to change the Subject, not 나(na) but 저(jeo).
저(jeo) is the word to mention myself formally so it can get along with 요(yo).
That's the way to say "I will not give up" in Korean.
Conclusion:
na jeal dae po gi an hae/나 절대 포기안해 in the informal way.
jeo jeal dae po gi an hae yo/나 절대 포기 안해요 in the formal way.
