“在周末”的英语?1.on weekends2.at weekends3.on the weekend4.at the

都对,on weekends好像强调每个周末,其它的区别不是太清楚了.
on the weekend
The club got all the members together on the weekend.
俱乐部使全体成员在周末举行了一次联允.
We had a good time on the weekend party.
我们在周末聚会上玩得很快乐.
You may go grass skiing,bicycle riding,or shopping on the weekend.
周末你可以去滑草,骑脚踏车,或购物.
at the weekend
在周末
例句与用法:
They live in London during the week and go to the country at the weekend.
他们从星期一到星期五都住在伦敦,周末到郊外去.
The office is closed at the weekend.
这个办事处星期六和星期日不办公.
`Where are you going at the weekend?' `Nowhere special (ie Not to any special place).'
‘你打算到哪儿去度周末?’‘无处可去.’
If need be,I can do extra work at the weekend.
必要时我可以在周末加班.
at weekends
（＝on weekends）在周末
例句与用法:
They like to go ballooning at weekends.
他们周末喜欢乘气球玩.
I often fish/go fishing at weekends.
我常在周末去钓鱼.
We love to get out into the countryside at weekends.
我们周末爱到郊外去玩儿.
He likes to go climbing at weekends.
他喜欢在周末做登山运动.
Discipline is often relaxed at weekends.
一到周末纪律往往松弛下来.
I will be at liberty only at weekends.
我只有在周末才有空.
He likes to watch farces at weekends to relax himself.
他喜欢在周末看滑稽剧来放松自己.
I often go to visit my aunt at weekends.
我常在周末去看望我姑母.

4 is correct.
Based on the rule of English
at the weekend
在周末
例句与用法:
They live in London during the week and go to the country at the weekend.
他们从星期一到星期五都住在伦敦, 周末到郊外去.
...

on weekends
maybe right

1.2.3.4均可，但有区别。
1和2相同，只是1是美式用法。3.4应该也相同，美国更多用on.
而at/on weakends 是指广泛的周末,意倾向于每周末.
at/on the weakend 是特指的某个周末.

all of them are correct

3.on the weekend