“每隔一个”， 英文怎么说

“每隔一个”
用 every other 即可。

每隔一个关一盏灯
turn off every other light

另举例句：
约翰每隔一个星期就复习一遍功课。
John brushes his lessons up once every other week.

每隔一个星期我们都到公园溜一趟。
We enjoy staying in the park every other Sunday.

turn off the lights at alternate points in a row

turn of the light, but not all of them, skip one between every two

turn off the lights,not all ,but scape one and close another one.