"우리는 개를 좋아합니다."
Translation:We like dogs.
There is not a specific particle for plural in Korea.. So here "kaerul" can be both "dog" or"dogs"..it just depends on the context..
들 is not really used. I've seen it used in plenty of language learning programs but rarely hear it used in actual conversation. Maybe it's used in books or newspapers though
This is anecdotal, but I was corrected by a Korean friend once for not using it when it would have made more sense to use it. I've heard though that it is only really used for people (사람들, 남자들, 학생들, etc) even though it's grammatically correct to use it with any noun.
Its used when explicity stating plurality is important. Otherwide, like many parts of conversational Korean, it can be omitted if the context makes it clear.
I think it has something to do with the -nun and the -rul ending that makes it so that they are talking about dogs in general.
It isn't plural or singular based on the particle, but on the context. If you said this with a dog around or while talking about a specific dog, you'd be saying "we like the dog". If no dog is around, you'd be assumed to be saying "we like dogs". If a dog is around or have been talking about a dog and you want to specifically say you like dogs (plural), you would add the plural particle (들), so it'd be "우리는 개들 좋아해요".
는 is the subject marker and 를 is the object marker. The Korean language is ALL about context, so plurals aren't really used. Numbers if necessary can be applied, or qualifiers, like, ALL dogs, but the language requires you to pay attention to the conversation and determine if the speaker/writer is talking about one dog specifically or dogs in general.