Best answer
\_\_ 선생님 감사합니다.
\_\_ sensei arigatou gozai mashita.
Thank you \_\_sensei.
\_\_ 선생님 감사합니다.
\_\_ sensei arigatou gozai masu.
Thank you \_\_sensei.
\_\_ 선생님, 정말 감사했습니다.
\_\_ sensei, doumo arigatou gozai mashita.
Thank you very much, \_\_sensei.
\_\_ 선생님 감사합니다.
\_\_ sensei kansha shiteimasu.
I am thankful for you, \_\_sensei.
\_\_ 선생님 덕분에 \_\_ 수있었습니다.
\_\_ sensei no okaged, \_\_ga dekimashita
- because \_\_sensei taught me / helped me, I could do \_\_ very well.
- because\_\_sensei taught me / helped me, I exceeded in doing \_\_
\_\_ 선생님 감사하겠습니다.
sensei ni arigataidesu
I am thankful for \_\_sensei.
Answer
It depends on what situation, really. In usual situation, to show respect you can say : “Sensei, doumo arigatou gozaimasu / gozaimashita.”And don “t forget to bow after that! Action speaks louder than words.
If you are leaving for good, or your Sensei is and presumably you will not see each other easily for a very long time, you can add “Taihen osewa ni narimashita”after saying “doumo arigatou gozaimashita. And again don”t forget to bow after that.