how to express the meaning of"吓死我了"
for example,吓死我了，我还以为我说错话了呢。
吓死我了，你以后别突然在后面拍我
as you know, the same"吓死我了" in chinese have different meanings,so how to express them??

and another question is that when i talk to my friends,really close friends.how to say "你个死变态 or 你白痴吧你" in English

thx a lot

Question

how to express the meaning of"吓死我了"
for example,吓死我了，我还以为我说错话了呢。
           吓死我了，你以后别突然在后面拍我
 as you know, the same"吓死我了" in chinese have different meanings,so how to express them??

and another question is that when i talk to my friends,really close friends.how to say "你个死变态 or 你白痴吧你" in English

thx a lot

Answer

I think the best and most direct translation is: 'you scared me to death!' As below:
吓死我了，我还以为我说错话了呢。 You scared me to death, I thought I said something wrong!!
吓死我了，你以后别突然在后面拍我  You scared me to death, next time dont surprise me from behind!!

What Linda said souds OK for this:
你个死变态 you freak! 
你白痴吧你 you idiot!

Answer

吓死我了，我还以为我说错话了呢。Thank God I didn't say the wrong thing.
吓死我了，你以后别突然在后面拍我 You scare me!  Don't suddenly pat on my back like that again.
你个死变态 you freak!
你白痴吧你 you idiot!

Answer

interesting topic: Maybe not quite suitable for your example, but is "scare the bejesus out of sb." one ? :)

Answer

我想你應該是想問英文該怎麼說吧.

You freaked me out.

另外一個我覺得不錯可以分享的(電影裡聽到的)：
You take my breath away
不完全一樣,但是很生動的