Yes, it looks like I will need some translation.
The one bit of Japanese they have on my testing requirements says:
Koszonom (accent marks missing, but means thank you in Hungarian) is equivalent to arigato gozaj masz.
Definitely not something they will be able to explain, so I think your right - time to ask someone who knows japanese better. (Like Professor Goldsbury)
You sent me a PM, but I will answer your question here.
Since you asked about the beginning of class, I dod not bother so much about the end, but, of course, it is customary to thank one's partner after training--after each waza, or after the class as a whole.
The basic pattern is Arigatou gozaimashita
ありがとうございました, or, if you like some kanji as well: 有り難うございました. This means 'thanks for what has (just) happened' = thank you for training in the last waza / in the class that has just finished.
The addition of doumo
どうも adds a certain intensity, as in doumo arigatou gozaimashita
and this is what we all say to each other after training in my own dojo. Of course, it comes naturally to my students, who are native Japanese and say it millions of times in their lives--always correctly.
However, Japan has a strictly hierarchical society (especially in budo circles) and there are various subtle nuances to such a basic form of utterance as giving thanks for favours received. So, it would be considered somewhat impolite for a junior to say doumo arigatou
to a senior, but it would not be impolite the other way round. A junior can say to a senior either arigatou gozaimashita
, or doumo arigatou gozaimashita
, but a senior can add the third alternative, which is doumo arigatou
or doumo doumo
has a different meaning in Japanese.)
is the past
tense of a verb. The present
tense is gozaimasu
. What is the difference in usage? Well, if you take a train here in Japan, the train conductor will usually thank you for travelling on the train. He / she will say, (makoto ni) arigatou gozaimasu
. That is, the journey is just beginning. Just before you get off, the conductor will thank you for having travelled on the train and will say, (makoto ni) arigatou gozaimashita
. That is, the journey has almost finished and will shortly become past.
You can safely ignore makoto ni
, by the way. It means something like 'sincerely' in English and it would be odd to use it in the dojo.