Learn Korean: Verb + 서/같지 않다

Let’s take a look at the Korean sentence pattern Verb + 서/같이 않다. We use this when someone acts like a different person because his actions and words contradict the usual him. If my brother who is known for this tough character chickens out and refuses to ride the roller coaster with me, I would say You are not yourself because you're scared. The main verb is 두려워하다 (to be scared). We take the verb stem (두려워하) and conjugate it into its 아/아/여 form (두려워해). Then, we attach 서 (두려워해서). This part means because you're scared. Next is the name/title of the person. I call my brother 오빠 because he is older than me (if I was a girl). Then, we add 같지 않다. This part means you are not like (you). The actual sentence is 두려워해서 오빠 같지 않아(요).

독기가 다 빠져서 강태하 같지 않아.
You lost your edge. You are not yourself.

겁이 나서 오빠 같지 않아.
The oppa I know is never scared of anything. But why are you chickening out now.

욕해서 누나 같지 않아.
The noona I know never cusses. You don't seem like the noona I know.