Purpose: This study examines English performance on a set of 11 grammatical forms in Spanish-English bilingual, school-age children in order to understand how item difficulty of grammatical constructions helps correctly classify language impairment (LI) from expected variability in second language acquisition when taking into account linguistic experience and exposure. Method: Three hundred seventy-eight children's scores on the Bilingual English-Spanish Assessment-Middle Extension (PeA+-a, Bedore, GutiA(C)rrez-Clellen, Iglesias, & Goldstein, 2008) morphosyntax cloze task were analyzed by bilingual experience groups (high Spanish experience, balanced English-Spanish experience, high English experience, ability (typically developing [TD] vs. LI), and grammatical form. Classification accuracy was calculated for the forms that best differentiated TD and LI groups. Results: Children with LI scored lower than TD children across all bilingual experience groups. There were differences by grammatical form across bilingual experience and ability groups. Children from high English experience and balanced English-Spanish experience groups could be accurately classified on the basis of all the English grammatical forms tested except for prepositions. For bilinguals with high Spanish experience, it was possible to rule out LI on the basis of grammatical production but not rule in LI. Conclusions: It is possible to accurately identify LI in English language learners once they use English 40% of the time or more. However, for children with high Spanish experience, more information about development and patterns of impairment is needed to positively identify LI.