Can explicit grammar lessons help kids with language disorder?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Study participants will include children with language impairment, aged 5 through 9 years. Participants will not have any indication of other significant conditions to which their impairment may be attributed, such as autism spectrum disorder, Down syndrome, seizure disorder, or hearing impairment. Participants with a diagnosis of attention deficit/hyperactivity disorder will be included due to high rate of co-morbidity (see Redmond, 2016). Additionally, participants will meet the following criteria: * No evidence of significant cognitive delay; * Evidence of language impairment; * Evidence of deficits on expressive grammatical forms: score below 30% accuracy on at least two of the following forms: third person singular -s, regular past tense -ed, auxiliary is/are in statements, auxiliary do/does in questions; * Typical hearing and vision, with correction if necessary; * Native English speaker with English spoken in the home by at least one primary caregiver since birth; * Speaker of Mainstream American English; * Be able to articulate final-position phonemes /s/, /z/, /t/, and /d/; and * Majority of utterances (\> 50%) include subject and verb in obligated contexts based on a 20-min conversational language sample to ensure appropriateness of study intervention. Exclusion Criteria: Participants will be excluded if there is no indication of language impairment, and they are not aged 5 through 9 years. Participants will also be excluded if there is indication of other significant conditions to which their impairment may be attributed, such as autism spectrum disorder, Down syndrome, seizure disorder, or hearing impairment. Additionally, participants will be excluded in they meet the following criteria: * Evidence of significant cognitive delay; * No evidence of deficits on expressive grammatical forms: score below 30% accuracy on at least two of the following forms: third person singular -s, regular past tense -ed, auxiliary is/are in statements, auxiliary do/does in questions; * Atypical hearing and vision, with correction if necessary; * Non-native English speaker; * Speaker of Non-mainstream American English; * Unable to articulate final-position phonemes /s/, /z/, /t/, and /d/; and * Non-majority of utterances (\< 50%) include subject and verb in obligated contexts based on a 20-min conversational language sample to ensure appropriateness of study intervention.