[mountaineer22]

If language is required for forming memories, surely babies that have learned sign-language would remember something, no?

https://en.wikipedia.org/wiki/Hyperthymesia

As a bilingual person, do you dream in both languages, or one particular language?

[mirekrusin]

In my case after living in another country for about 3-6 months I've started having dreams in new language. It came more less together with having inner dialogue in the head in new language. New one replaced the old one.

[Retra]

That just means your language is part of your memory, not that it is necessary for it to function.