Asking about sizes
Do you have a bigger size of this clothing?
Textbook이 옷의 더 큰 사이즈가 있습니까?i os-ui deo keun sa-i-jeu-ga it-seum-ni-kka?
Real이거 한 치수 큰 거 있어요?i-geo han chi-su keun geo it-seo-yo?
치수 means clothing size. 한 치수 큰 거 = one size up. You can also just hold it up and say 이거 M 있어요? (do you have this in M?). Korean sizing uses S/M/L or 44/55/66.
Haggling at a market
Could you lower the price a little?
Textbook가격을 좀 낮춰 주실 수 있나요?ga-gyeo-geul jom nat-chwo ju-sil su it-na-yo?
Real좀 깎아주세요~ / 에이, 좀 빼주세요jom kka-kka-ju-se-yo~ / e-i, jom ppae-ju-se-yo
At Korean markets, 깎다 (to shave off) is THE haggling word. 좀 깎아주세요 with a smile works wonders. Adding 에이~ (come on~) shows you're playing the game. Never haggle in department stores though.
Greeting a friend
Hello, have you been well?
Textbook안녕하세요, 잘 지내셨어요?an-nyeong-ha-se-yo, jal ji-nae-syeoss-eo-yo?
Real야, 밥 먹었어?ya, bap meo-geoss-eo?
밥 먹었어? (have you eaten?) is the classic Korean greeting between friends. It doesn't literally ask about food — it's like asking "how are you?" Answering about your actual meal is perfectly fine too.
Saying something is delicious
This food is delicious
Textbook이 음식이 맛있습니다i eum-si-gi ma-sit-seum-ni-da
Real이거 미쳤다i-geo mi-chyeot-da
맛있다 is correct but boring. 미쳤다 (literally: insane) is the go-to real reaction when food is amazing. You'll hear this in every K-drama eating scene.
Ordering coffee
One iced americano please
Textbook아이스 아메리카노 한 잔 주세요a-i-seu a-me-ri-ka-no han jan ju-se-yo
Real아아 하나요a-a ha-na-yo
Koreans abbreviate 아이스 아메리카노 to 아아. The 주세요 (please) is dropped — 요 at the end is polite enough. At busy cafes, shorter = better.