by是什么时态的标志词

by是完成时的标志词by+过去的时间，用过去完成时；by+现在的时间，用现在完成时；by+将来的时间，用将来完成时。

例句

He was a loner by nature and by inclination.

他天性不喜交际，且自己也无意于此。

Nocturnal animals sleep by day and hunt by night.

夜间活动的动物白天睡觉晚上猎食。

By the 1920s, he was lionized by literary New York.

20世纪20年代前，他被纽约文学界所吹捧。

By night, the perimeter wire was illumined by lights.

夜晚，周遭的铁丝网都被灯光照亮。