Good morning. Good afternoon.  Good evening. = 안녕하세요?   안녕하십니까? (F)    Annyong haseyo?    Annyong hashimnikka? (F)

Good-bye. (to person leaving) = 안녕히 가세요.   안녕히 가십시오. (F)    Annyonghi kasayo.  Annyonghi kashipshiyo. (F)

Good-bye. (to person staying) = 안녕히 계세요.   안녕히 계십시오. (F)    Annyonghi kyesayo.   Annyonghi kyeshipshiyo (F)

Good night. = 안녕히 주무십시요. (F)  Annyonghi jumushipsiyo. (F)

How do you do? (meeting for the first time) = 처음 뵙겠습니다. (F)       Ch'oum poepgetsumnida. (F)

My name is _____. = 저는 ___ 입니다. (F)   Chonun ______ imnida. (F)

How are you? = 어떠십니까? (F)   Ottoshimnikka? (F)

Hello? (on the phone) = 여보세요?  Yoboseyo?

Do you speak English? = 영어를 할수 있어요?  Yeongeorul malsum halsu isseoyo?

Yes. = 네 Ne

No. = 아니요 Aniyo

Thank you. = 감사합니다. (F) kamsahamnida

I am sorry. = 미안합니다. (F) mianhamnida

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(F) means formal

for the informal, once I find out the informal way, I'll add more :)