As If vs. As Though

As if and as though mean the same. They are used to say what a situation seems like. It looks as if/as though it is going to rain.

Tenses

To show that a comparison is unreal, we use a past tense with a present meaning after as if/as though.

• She looks as if/as though she is rich. (Perhaps she is rich.)
• She looks as if/as though she was rich. (She is not rich.)

In a formal style, were can be used instead of was to show that a comparison is unreal.

• She looks as if she were rich.

Note that we do not use a past perfect for a past unreal comparison.

• She looked as if she was rich, but she wasn’t. (NOT — as if she had been rich.

In an informal style, like is often used instead of as if/as though. This is common in American English.

• It looks like it is going to rain.