The instrument was bought by my grandfather many years

问题描述:

The instrument was bought by my grandfather many years

by: "被"
by sb.:用于被动态

介词,不用翻译的,整句的意思是这仪器是我祖父很多年前买的。

The instrument was bought by my grandfather many years ago
这件乐器是由我祖父许多年前买的.
by由;经由