516　after you leave还是after you will leave ——需要用一般现在时代替一般将来时的从句

1　如果主句的谓语动词用一般将来时，由after, before, when, until, if, as soon as等连词引导的从句中的谓语动词，要用一般现在时表示将来，而不可直接用一般将来时。

你走后，我将经常给你写信。

After you leave , I shall often write to you. （正）

After you will leave , I shall often write to you. （误）

We won't leave before she comes back . （正）在她回来前，我们不会离开 。

We won't leave before she will come back . （误）

I shall call on you if it's fine tomorrow .（正）如果明天天气好，我就去看你 。

I shall call on you if it will be fine tomorrow . （误）

2　如果主句是祈使句，这类从句也要用一般现在时。

Please wait here until he returns . （正）请在这里等，直到他回来 。

Please wait here until he will return . （误）

As soon as she arrives , let me know.（正）她一到就马上告诉我 。

As soon as she will arrive , let me know.（误）