从现在起: from here on out

例句与用法:

From here on out, you're going to watch him closely.

从现在起，你要严密监视他。

从现在开始: from now on

例句与用法:

From now on you are free.

从今以后你自由了。

From now on we'll study hard.

从这儿以后，我们要好好学习。

We must study harder from now on.

从今以后我们必须更努力学习。