Meaning of guài shì:
guài shì
怪事
Noun
strange thing; curious occurrence
Zuó wǎn fāshēngle yī jiàn guài shì, wǒ fángjiān lǐ de zhōng tūrán tíng le.
昨晚发生了一件怪事,我房间里的钟突然停了。
A strange thing happened last night; the clock in my room suddenly stopped.
Gāngcái de qíngkuàng zhēn shì guàishì.
刚才的情况真是怪事。
The situation just now was truly a curious occurrence.