Tense and plural formation in Welsh-English bilingual children with and without language impairment.

Background: Grammatical morphology has been shown to be problematic for children with specific language impairment (SLI) or developmental language disorder (DLD). Most research on this topic comes from widely spoken languages, such as English. Despite Welsh being the most extensively spoken indigenous in the UK after English, and Wales being the only official bilingual country in the UK, our knowledge about the morphosyntactic areas of Welsh that may pose problems for Welsh-speaking children with SLI is limited.