Chinese phrase
怪不得 guài bu de
Meaning
no wonder
When to use it
Shows that a result is not surprising for a known reason. It often introduces a reason that has just become clear and can sound mildly emphatic.
Example dialogue
他怎么弹得这么好？ tā zěn me tán de zhè me hǎo
How does he play so well?
怪不得，他从小学习钢琴，已经学十年了。 guài bu de tā cóng xiǎo xué xí gāng qín yǐ jīng xué shí nián le
No wonder he plays so well - he started learning piano as a child and has studied for ten years.