Very confused about "には" in indicating relationships


I read a very detailed and useful answer explaining the difference between "に"
and "には" but am still confused about a sentence I recently encountered.

私たちには息子が二人います。

I do not understand the function of には in this sentence. I get the general
meaning -- that the speaker and their partner have two sons, but beyond that
my brain is sort of melting. Please help. :c




This is a topicalization of the に-marked (a.k.a., dative) subject 私たち. 息子 is a
が-marked (a.k.a, nominative) object.

Basically, what you are missing (judging by your comment on @torazaburo's
answer) is that に can be used as a subject marker given certain predicates. I
talk about this in detail in this answer: [What is the difference between "に"
and "には"?](https://japanese.stackexchange.com/questions/1096/what-is-the-
difference-between-%E3%81%AB-and-%E3%81%AB%E3%81%AF/11021#11021)




This is a topicalization of the に-marked (a.k.a., dative) subject 私たち. 息子 is a
が-marked (a.k.a, nominative) object.

Basically, what you are missing (judging by your comment on @torazaburo's
answer) is that に can be used as a subject marker given certain predicates. I
talk about this in detail in this answer: [What is the difference between "に"
and "には"?](https://japanese.stackexchange.com/questions/1096/what-is-the-
difference-between-%E3%81%AB-and-%E3%81%AB%E3%81%AF/11021#11021)

