Answered for language learning in general. No specific language was set for this question, so the findings are drawn from general second-language research rather than one language’s literature.
The available sources most relevant to this question focus on ADHD's impact on language learning and offer some practical direction: ADHD symptoms (especially attention difficulties) are strongly linked to weaker second-language performance, but adults with ADHD also report specific strategies and even some strengths (like being talkative and socially fearless in speaking) that can be leveraged. The clearest practical guidance is to break tasks down, manage attention/distraction deliberately, choose the language "modality" (reading, writing, speaking, listening) that matches an individual's strengths, and address executive-function and motivation needs directly rather than assuming a one-size-fits-all classroom method will work.
In a study of primary-school children, the severity of ADHD symptoms was a stronger predictor of second-language learning performance than IQ was — ADHD symptom level explained about 47% of the variation in language scores, compared to only about 10% explained by IQ.4
In plain terms
Adults with ADHD report that inattention, working-memory difficulties, hyperactivity/impulsivity, and sometimes 'hyperfocus' (an intense, absorbed concentration on one activity) all shape how they learn and use additional languages — for example, losing track of a conversation in another language and struggling to re-engage, or making frequent typos in writing that they only catch on a careful re-read.5
In plain terms
Example
There is no consistent pattern across people with ADHD for which skill (reading, writing, listening, or speaking) is hardest or easiest — some report being much stronger at reading/writing and struggling with spoken conversation, while others describe themselves as 'fearless,' talkative, and socially confident speakers who find written language more difficult.5
Example
Contrary to what one might expect, adults with ADHD do not appear to have notably more trouble understanding indirect meanings like irony or metaphor in a language compared to people without ADHD, based on comprehension testing.5
Some adults with ADHD report that starting medication improved their ability to pay attention during conversations or classroom instruction, which in turn helped with language learning.5
A study of English-as-a-second-language teaching for children with ADHD concludes that children with ADHD can fully master a second language, but teachers need to understand each child's individual needs, vary activities (individual, pair, and group work), stay flexible when a planned activity isn't working, and keep motivation central to instruction, rather than relying on old rote memorization and repetition methods.1
Example
Children with ADHD have a notably increased likelihood of also having language impairments or difficulties, and this overlap can complicate language learning; some researchers argue that ADHD's effect on executive functions (like planning, working memory, and self-control) undermines both academic learning and language/literacy development together.2,3
In plain terms