피곤합니다

난 안 피곤해 / 저는 안 피곤해요 = I'm not tired 난 안 졸려 / 저는 안 졸려요 = I'm not sleepy

Same as Shannon above. Also, 나 졸려 / 저는 졸려요 = I'm sleepy. English speakers often interchange "sleepy" and "tired". ;)

I'm tired : 난 피곤해(informal) 전 피곤해요, 피곤해요(formal) I'm not tired : 안 피곤해요(formal) 안 피곤해(informal)

I am tired. = 나 피곤해. I am tired of it = 그것에 지쳤어. (=I am sick of it. = I am fed up with it =지겨워)