参见：费力[fèilì]

• 白费劲

  waste effort

• 这件事很费劲。

  This matter is very difficult.

• 腿脚不好，上楼费劲。

  My legs and feet are weak, so walking up stairs takes a lot of effort.

• 费了半天劲，也没有干好。

  I spent ages on it and still didn't get it done.