ohayō gozaimasu Good morning
  konnichiwa Hello
  konbanwa Good evening
  oyasumi nasai Good night
  ja, mata Bye / see you again
  sayōnara Goodbye
  arigatō Thanks
  arigatō gozaimasu Thank you
  dō itashimashite You're welcome
  sumimasen Excuse me
  gomen nasai Sorry
  wakarimasen I don't understand
  kekkō desu I'm OK, no thank you
  dōzo Please accept this / go ahead
  o-genki desu ka How are you?
  hai, genki desu I'm fine

 

Useful Links

 

  JSNW Hiragana, Katakana and Kanji flash cards
  AiueAoi Learn hiragana with sound