The role of the basal ganglia, and more specifically of the striatum, in language is still debated. Recent studies have proposed that linguistic abilities involve two distinct types off processes: the retrieving of stored information, implicating temporal lobe areas, and the application of combinatorial rules, implicating fronto-striatal circuits. Studies of patients with focal lesions and neurodegenerative diseases have suggested a role for the striatum in morphological role application, but functional imaging studies Found that the left caudate was involved in syntactic processing and not morphological processing. In the presen t study, we tested the view that the basal ganglia are involved in rule applicat ion and not in lexical retrieving in a model of striatal dysfunction, namely Hun tington’s disease at early stages. We assessed the rule-lexicon dichotomy in t he linguistic domain with morphology (conjugation of non-verbs and verbs) and s yntax (sentence comprehension) and in a nonlinguistic domain with arithmetic ope rations (subtraction and multiplication). Thirty Huntington’s disease patient s (15 at stage I and 15 at stage II) and 20 controls matched for their age and cultural level were included in this study. Huntington’s disease patients were also assessed using the Unified Huntington’s Disease Mating Scale (UHDMS) and MM. We Found that ea rly Huntington’s disease patients were impaired in rule application in the ling uistic and non-linguistic domains (morphology, syntax and subtraction), whereas they were broadly spared with lexical processing. The pattern of performance wa s similar in patients at stage I and stage II, except that stage II patients wer e more impaired in all taste assessing rules and had in addition a very slight i mpairment in the lexical condition of conjugation. Finally, syntactic rule abili ties correlated with all markers of the disease evolution including bicaudate ra tio and performance in executive Function, whereas there was no correlation with arithmetic and morphological abilities. Together, this suggests that the striat um is involved in rule processing more than in lexical processing and that it ex tends to linguistic and non-linguistic domains. These results are discussed in terms of domain-specific versus domain-general processes of rule application. The role of the basal ganglia, and more specifically of the striatum, in more specifically of the striatum, in language of still striking, in particular of the striatum, in language of the striatum, in more specifically of the striatum, in the language of the striatum, and more specifically of the striatum, in the language of the striatum, rules, implicating fronto-striatal circuits. Studies of patients with focal lesions and neurodegenerative diseases have suggested a role for the striatum in morphological role application, but functional imaging studies Found that the left caudate was involved in syntactic processing and not morphological processing. In the presen t study, we tested the view that the basal ganglia are involved in rule applicat ion and not in lexical retrieving in a model of striatal dysfunction, namely Hun tington’s disease at early stages. We assessed the rule-lexicon dichotomy in t he linguistic domain with morphology (conjugation of non-verbs and verbs) and s yntax (sentence comprehension) and in an onlinguistic domain with arithmetic operations (subtraction and multiplication). Thirty Huntington’s disease patients s (15 at stage I and 15 at stage II) and 20 controls matched for their age and cultural level were included in this study. Huntington’s disease patients were also also assessed using the Unified Huntington’s Disease Mating Scale (UHDMS) and MM. We Found that ea rly Huntington’s disease patients were impaired in rule application in the linguistic and non-linguistic domains (morphology, syntax and subtraction), they they were broadly spared with lexical processing. The pattern of performance wa s similar in patients at stage I and stage II, except that stage II patients wer e more impaired in all taste assessing rules and had in addition a very slight i mpairment in the lexical condition of conjugation. Finally, syntactic rule abili ties correlated with all markers of the disease evolution including bicaudate raio and performance in executive function, there there wasno correlation with arithmetic and morphological abilities. Together, this suggests that the striat um is involved in rule processing more than in lexical processing and that it exordinary to linguistic and non-linguistic domains. These results are discussed in terms of domain-specific versus domain-general processes of rule application.