Going to a Karaoke With a Friend

노래를 잘 불러요. [no-rae-reul jal bul-reo-yo]
I sing well.

• 노래를 [no-rae-reul] means "song"
• 잘 [jal] means "well"
• 불러요. [bul-reo-yo] means "I sing."

노래를 잘 못 불러요. [no-rae-reul jal mot bul-reo-yo]
I don't sing well.

• 잘 못 [jal mot] means "not well"

춤을 잘 춰요. [chum-eul jal chwo-yo]
I dance well.

• 춤을 [chum-eu-l] means "dance"
• 잘 춰요. [jal chwo-yo] means "I dance well."

춤을 잘 못 춰요. [chum-eul jal mot chwo-yo]
I don't dance well.

• 잘 못 춰요. [jal mot chwo-yo] means "I don't dance well."

More examples:

• 요리를 해요. [yo-ri-reul hae-yo] I cook.
• 요리를 잘 해요. [yo-ri-reul jal hae-yo] I cook well.
• 요리를 잘 못 해요. [yo-ri-reul jal mot hae-yo] I don't cook well.

• 피아노를 쳐요. [pi-a-no-reul chyeo-yo] I play piano.
• 피아노를 잘 쳐요. [pi-a-no-reul jal chyeo-yo] I play piano well.
• 피아노를 잘 못 쳐요. [pi-a-no-reul jal mot chyeo-yo] I don't play piano well.

• A: 우와, 노래를 잘 불러요!
  Wow, you sing well.
• A: 혹시 춤도 잘 춰요?
  By any chance, are you good at dancing too?
• B: 춤을 잘 못 춰요. [chum-eul jal mot chwo-yo]
  I don't dance well.
• A: 아 그래요?
  Oh, really?
• A: 이번엔 제가 불러볼게요
  This time, I'll sing!
• B: 춤을 잘 춰요. [chum-eul jal chwo-yo]
  You dance well.
• A: 정말요? 감사합니다!
  Really? Thank you!