More Japanese Greetings
Be aware YES or NO in Japanese:
When you would like to say "Yes", you can say this. This is a polite expression.
はい。 hai ええ。ee
When you would like to say "No", you can say this.
However, if the questioner's assumption can be seen as negative, and you agree with the negative assumption, please answer "Yes". If you disagree with the assumption, please answer "No". To avoid confusion, it would be safer to add what it was assumed.
(You do not have any Japanese friends, do you?)
いいえ、（ともだちは）います。(Actually, I do)
はい、（ともだちが）いません。(No, I don't have any.)
When you express your understanding, you can say these. These are polite expressions.
I don't understand.
When you go to bed:
When you go to bed, you can say this. This is a polite expression.
When you say good night to your friends, you can say this.
Very Japanese greetings:
When you express your appreciation to someone, you can say this. This is a polite expression. There are two possible situations.
よろしくおねがいします。 Yoroshiku Onegaishimasu
1) Please to meet you. (Used with self-introduction)
There is another meaning for this expression.
2) Thank you in advance. (When you ask something)
To your friends, you still can use this expression as a shortened version.
Thanks! (Not sure in English ^^;)
There is a similar expression to express your appreciation. You can also use this one both situation, self-introduction and asking a favour. "Osewani narimasu" is more often used in formal situations.
おせわになります。 Osewani narimasu
Please to meet you. / Thank you in advance.
Note: "お世話になっています: Osewani natteimasu" is used as a business greeting, which is different.
When you eat:
When you express your appreciation of the meal and start eating, you can say this. This is a polite expression.
Thank you for the meal. (I will enjoy it.)
When you express your appreciation of the meal after eating, you can say this.
ごちそうさまでした。 Gochisou samadesita
Thank you for the meal. It was a great meal.
Express your apologies:
You can use this expression to express your sincere apologies. This is a polite expression.
ごめんなさい。 gomen nasai.
My apologies. / I'm sorry.
When you would like to say this to your friends, you can say this.