The knife is not sharp enough and need grinding.

这刀不快，需要磨了。

youdao

Knife unpleasant, grinding stone. People do not, there are places.

刀不快，石上磨。人不会，世上学。

youdao

Knife is not quick, stone grinding. No one can go to school.

刀不快，石上磨。人不会，世上学。

youdao

The mating song of the male has been described as beginning with a resonant rattle, continuing with a pop-like a cork being pulled from a wine bottle, followed by the pouring of a liquid out of a narrow-necked bottle and ending with the sound of knife grinding.

BBC: Capercaillie extinction fears ruffle feathers