dream about 梦想，梦见，梦到

【例句】
I dream about him, dreams so vivid that they disturb me for days.
我几次梦见了他，梦境如此逼真，我好几天都心神不宁。

Still we must climb and dream about what's at the top of our mountain.
不过,我们还是得攀爬，梦想着我们的山顶上会有什么。