title: The acquisition of the English verbal auxiliary and copula in normal and linguistically deviant children.
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007804:Language Development; D007806:Language Disorders / Q000150:complications* / Q000628:therapy; D008037:Linguistics; D008297:Male; D013070:Speech Therapy; D013997:Time Factors