Every cloud has a silver lining. 塞翁失馬，焉知非福

"Every cloud has a silver lining." -----something that you say which means that there is something good even in an unpleasant situation.  Eg.As the trip's been cancelled I'll be able to go to the match this Saturday. Every cloud has a silver lining.

 

be head over heels

be head over heels (in love)

to be in love with someone very much, especially at the beginning of a relationship.

 

eg. It's obvious that they're head over heels in love with each other.

(head over heels 照字面上的意思是頭朝下摔倒，另一引申義就是completely, uncontrollably完全地，失控地。所以，head over heels in love 就是熱戀中囉！)

Give sb an inch (and they'll take a mile) 得寸進尺

:" Give sb an inch and they'll take a mile." means if you say yes to sb for a small request, they will want much more. (in Chinese, this idiom is 得寸進尺，食髓知味)

Eg. I said Jerry could borrow my car occasionally, and then he started to borrow it every night! Give him an inch!

a pig in a poke

"a pig in a poke" means something one has bought without seeing or examining it and that one may then find to be worthless.

Eg. You can buy the used TV if you want but it will be like buying a pig in a poke.