To describe something that seems like it's happening or is being imagined.
He was daydreaming, staring out the window as if he was somewhere else.
他正在做白日梦,盯着窗外,好像他去了别的地方。
To express that something is surprising or hard to believe.
She's so calm, as though the news didn't affect her at all.
她如此冷静,好像新闻对她一点影响都没有。