在时间状语从句中(以when, after, before, while, until, as soon as等引导)和条件状语从句中(以if,unless引导),用一般现在时代替一般将来时,句子可以有将来时间
Please ring me up as soon as you arrive in Germany.(你一到德国就给我打电话)
人的心理活动和感官动作一般用一般现在时而不用现在进行时表达,常见动词有:like, love, hate, dislike, want, wish, hope, think(认为),understand, remember, forget, mean, need, hear, feel, see.
I think it is going to snow.(我想天要下雪了)