This study investigated whether children with autism have atypical development of morphological and syntactic skills, including whether they use rote learning to compensate for impaired morphological processing and acquire grammatical morphemes in an atypical order. Participants were children aged from 3-6 years who had autism (n = 17), developmental delay without autism (n = 7), and typically-developing children (n = 19). Language samples were taken from participants during the administration of the Autism Diagnostic Observation Schedule, and transcripts were coded using the Index of Productive Syntax, and for usage of Brown's grammatical morphemes. Participants were also administered an elicitation task requiring the application of inflections to non-words; the Wugs Task. The main finding of this study was that children with autism have unevenly developed morphological and syntactic sub-skills; they have skills which are a combination of intact, delayed, and atypical. It was also found that children with autism and children with developmental delays can acquire and use morphological rules. The implications of these findings are that, in order to maximize language acquisition for these children, clinicians need to utilize comprehensive language assessment tools and design interventions that are tailored to the child's strengths and weaknesses.