Both of those are correct.Sorry, I forgot to ask: isn't it correct to say a bottle with water in it or a bottle with some water in it ?
I don't think the "in it" is necessary.
I would use "in it" if the presence of water in the bottle would be unexpected:
It's exactly the same in my native language and that's why I asked that question. I'm doing a video with my students and one of the scenes shows a girl putting a plastic bottle in a laptop bag. There's some water in the bottle but it's not even half full. Now, in the pdf that comes with the video there are activities for each episode and a summary. In one place of the summary it says that the girl puts a bottle of water in the laptop bag. I had doubts about it since there wasn't a full or even nearly full bottle of water - there was less than half a bottle.In my English, "a bottle of water" is full or nearly full; more than 3/4 full, let's say.
There's a bottle with water in it in my bag. Use it to wash your flip-flops.
... in Australian English anyway.I don't think the "in it" is necessary.
There's a bottle with water in my bag. Use it to wash your flip-flops.
If it doesn't sound idiomatic in BrE if I say She put a bottle with water (in it) in the bag, then how can I say it naturally?Neither of your other suggestions are idiomatic.
I'd stick with "a bottle of water". If you don't like that, then I think it sounds better to use "some" (and, thinking about it a little more, I would add "in it"):If it doesn't sound idiomatic in BrE if I say She put a bottle with water (in it) in the bag, then how can I say it naturally?