This study investigates the production and online processing of English tense morphemes by sequential bilingual (L2) Turkish-speaking children with more than three years of exposure to English. Thirty-nine six- to nine-year-old L2 children and twenty-eight typically developing age-matched monolingual (L1) children were administered the production component for third person "-s" and past tense of the Test for Early Grammatical Impairment (Rice & Wexler, 2001) and participated in an online word monitoring task involving grammatical and ungrammatical sentences with presence/omission of tense (third person "-s", past tense "-ed") and non-tense (progressive "-ing", possessive "'s") morphemes. The L2 children's performance on the online task was compared to that of children with Specific Language Impairment (SLI) in Montgomery and Leonard (1998, 2006) to ascertain similarities and differences between the two populations. Results showed that the L2 children were sensitive to the ungrammaticality induced by the omission of tense morphemes, despite variable production. This reinforces the claim about intact underlying syntactic representations in child L2 acquisition despite non-target-like production (Haznedar & Schwartz, 1997).