use of 'arigatou' and 'arigatou gozaimasu' Hi, I'd like to know the difference in the use of 'arigatou' and 'arigatou gozaimasu'. First off, I do understand that 'arigatou' is the informal/casual way to say thanks while the other one is used formally. However, my question in this post is whether the use of 'arigatou' and 'arigatou gozaimasu' is based on how appreciative you are to the help/thing that you received or is it based on the person you're saying it to? E.g when receiving handouts/worksheets from my sensei, do I say 'arigatou' or 'arigatou gozaimasu'? Or is 'domo' okay? Another one, when the class has ended and I am leaving my class, do I say 'arigatou gozaimasu' or 'arigatou gozaimashita' to my sensei? I would really appreciate if someone could explain to me clearly and eliminate the confusion that I have now. Thanks.