だめだめ is used to express casually "No".
だめです Damedesu is more formal.
だめだ Dameda is telling your self "Impossiblle'
だめだよ Damedayo is telling someone "No"
This phrase has two meaning.
The literal translation is "Please forgive my bad manner."
(1) I am leaving.
(2) Excuse me.
When you are leaving, you usually say おさきに しつれいします。
"I am leaving now ... please forgive me for my bad manner."
Direct translation would be "Meet First Time".
This is a greeting you use when you meet someone for the first time.
"How do you dp?"
"Nice to meet you."
Kind of like those word.
"GANBARE" - "Hang in there." You say this to encourage someone who is working hard, such as running in a marathon or studying. Another way of saying this is "GANBATTE."
When you enter a restaurant, people usually say いらっしゃいませ。
It is a polite way of saying いらっしゃい。
It means welcome!!!
This is different from どういたしまして dou itashimashite ... means "You are welcome." or "Don't even mention it."
いいえ === No
You sometime say 「しょうがないか」「しかたないか」to reconfirming and justifying that fact that you given up.
Otsukaresama desu is a key phrase that you will need to master if you plan to work in Japan. Whever you meet someone who is more senior than you, you say おつかれさまです。
The straight translation of this phrase would be "being tired" ... This means, you are thanking someone for their hard work.
Noe: You do not use this term for someone is not your senior. You say 「おつかれ」「おつかれさま」... Never「おつかれさまです」