This is a list of language-related Stack Exchange sites. If your target language is not listed here, please consider creating a proposal on Area 51.
Sites about languages in general, but not about a specific language:
- Language Learning (this site)
- Constructed Languages (mostly about how to create new languages; not about learning them)
Language-specific sites, in alphabetical order by language:
- English: English Language & Usage & English Language Learners
On Psychology & Neuroscience Stack Exchange, some questions tagged
language-processing may be relevant to language learning.