sumi masen
I am sorry (formal), excuse me
Gomen(-nasai/-ne)
I am sorry (casual)
Itte kimasu
I am leaving home
Itte rasshyai
please go and come back
tadaima
I am home
okaeri(nasai)
Welcome back
Itadaki masu
Thank you for the meal (before)
Gochisoo same deshita
thank you for the meal (after)
Hajime mashite
Nice to meet you (for the first time)
Doozo yoroshiku
Pleased to meet you
yoroshiku onegai shimasu
pleased to meet you (formal)