Ｔａｌｋ Ｔｉｌｌ Ｓｏｍｅｏｎｅ ｉｓ Ｂｌｕｅ ｉｎ ｔｈｅ Ｆａｃｅ

Tammy: I don't know what to do about my father.

Mattle:What's wrong with him?

Tammy: It's his health. He doesn't take care of himself.

Mattle:Have you tried talking to him?

Tammy: I could talk to him till I'm blue in the face， and it wouldn't work.

Mattie: What about his doctor?

Talk till someone is blue in the face費盡唇舌

字面的意思為“講到某人的臉色發青為止”，形容苦口婆心勸解或“費盡唇舌”說服。例如： You can talk till you're blue in face about it.but it is not going to changeanything.(就算你講到口水干了，也不會有任何改變。)

Once in a blue moon難得一見地

blue moon(藍月亮)是指“一個月中的第二次滿月”。約每32個月才出現一次“一個月有兩次滿月”的天文現象。例如：You only clean your room once in a blue moon.(你會打掃房間還真是難得一見的事)。