sharpenings

grammar · medium

易错句子The sharpening the knife took ten minutes.

正确表达The sharpening of the knife took ten minutes.

sharpening 作名词表示“磨”这一动作时，后面要先用介词 of 引出逻辑宾语；直接在 sharpening 后跟名词，是把名词当成动词用了。

grammar · medium

易错句子There are many sharpening on the desk.

正确表达There are many sharpenings on the desk.

指削铅笔掉下的碎屑时，sharpening 是可数名词，复数形式为 sharpenings；many 后面必须接复数可数名词，所以不能直接用单数 sharpening。

grammar · medium

易错句子The sharpening of these knives are done by hand.

正确表达The sharpening of these knives is done by hand.

句子主语的中心词是单数名词 sharpening，of these knives 只是修饰成分，因此谓语要用单数 is，不能因为靠近复数 knives 就误用 are。