She's all talk.
→    입만살았어.

[예문]
A:That new emplpyee is big headache.
   새로들어온 직원때문에 골치아파.

B:Why? I find her interesting.
  왜? 재미있는 사람같던데?

A:Interesting doesn't cut it.
  재미있으면 뭘해?

B:She's all talk, and she doesn't even lift a finger.
  입만 살아가지고 손끝하나 까딱안해.