帮我看看这个英语句子这么写可以么？

You could go out to see film with your friends only if you've finished your homework.

You could go out to see film with your friends only if you finished your homwork.

都可以么？或者哪个对？

我觉得两个都不太对。

1） 看电影 watch movie/ film， 不用see
2）这个句子前后两句都是将来时态，Only if 和if 一样，引导条件从句，主句用将来，从句用现在表示将来。主句里面因为有情态动词can，所以时态不明显没关系；从句里的finish用现在时的原形就可以了。
3）这个句子的语气如果时严厉的，（你用了only if就是在强调条件，对么？）主句的情态动词用can会更贴切吧。（这里不可能是could过去式表示虚拟，只能理解为could表示语气缓和。）

所以，我建议句子改成：
You can go out to watch film with your friends only if you finish your homwork.

you can not go out to see a flim until you have finished your homework.

you cannot go out to see a film unless you have finished your homework.

下面的句子是对的 表示将来的虚拟语气

我觉得film 最好加s

You could go out to watch film with your friends only if you've finished your homework. 第一個好點,現在完成時,完成了一件再做另一件,第一件對後一件有影響.

下面的could改成can