Meaning of nán guài:
nán guài
难怪
Adverb
(it's) no wonder (that...); (it's) not surprising (that)
Tā měitiān duànliàn, suǒyǐ nánguài tā shēntǐ jiànkāng.
他每天锻炼，所以难怪他身体健康。
He exercises every day, so it's no wonder that he is healthy.
Tā zuótiān méi shuì hǎo, suǒyǐ jīntiān kàn qǐlái hěn lèi, nán guài le.
他昨天没睡好，所以今天看起来很累，难怪了。
He didn't sleep well yesterday, so he looks very tired today. It's not surprising.
