◆ 잘 먹겠습니다.
When you are invited to lunch or dinner at a Korean home, it is a polite gesture to thank the host for the meal they have prepared for you by saying 잘 먹겠습니다, which means “will enjoy this meal.” It is also nice to say 잘 먹었습니다 after you finish your meal to let them know that it was a nice meal, -겠-is a present tense marker, whereas, -었- is usually a past tense marker.
A : 어서 오세요. / Welcome.
B : 초대해 주셔서 감사합니다. / Thank you for the invitation.
A : 오늘은 한국음식을 준비했습니다. / We prepared some Korean food for you.
B : 그래요? 저는 한국 음식을 아주 좋아합니다. / Oh, that sounds nice. I like Korean food.
A : 많이 드세요. / Please help yourself.
B : 감사합니다. 잘 먹겠습니다. / Thank you.