"There are 1,500 cat photos in my cellphone."

Translation: 我的手机里有一千五百张猫的照片。

[hippietrail]

As a native English speaker I would only say "on my phone" just as I would say "on the TV" or "on the computer". For something like a battery or SIM card I would say "in" though.

[Chris349250]

我的手机里有一千五百张猫的照片。Is the final 的 really required?

[toutousmile]

Yes, because that 的 refers to photos 'of' cats

[Cat722536]

Again with that extra "的." It would make sense if it was 张照片的猫" because that would be "photos of cats," but the extra "的 in the accepted sentence I only put because it was provided. I don't really understand why you would say "猫的照片"

[roman2095]

As I understand it, in this sentence the 的 is not being used to indicate possession but is used to indicate that 猫 is an adjective before the noun 照片.

https://resources.allsetlearning.com/chinese/grammar/Modifying_nouns_with_adjective_%2B_%22de%22

[Kivolamuzikisto]

You're exactly right

[cynthiaspd]

I don't understand why it is cats (plural) and not photos (plural). Can anyone explain this?

[roman2095]

It is the other way around. It is "cat photos". "cat" is singular because it is an adjective qualifying "photos", and "photos" is plural because there are 1500 of them.