"It's raining outside, you need to take an umbrella with you when you go out."

Translation: 外面下着雨，你出去要带伞。

[gszeto]

Does it have to be 下着雨 instead of just 下雨?

[624qCWL9]

I think "...你出去要带雨伞" should be accepted too but I would like to hear a native speaker's opinion. Would it sound weird to say 雨伞 instead of just 伞?

[Cinnamon5230]

Yes, it is a bit weird in actual use. But it is definitely a valid sentence.

[Keith_APP]

It does not sound weird, but it depends on area which one is more common. Both should be considered as correct.

[ThieumL]

In Sichuan / Chengdu area they say 雨伞

[jesi807400]

Personally I prefer to use 雨伞 over just 伞