Purpose: The comprehension of tense/aspect morphology by children with autism spectrum disorder (ASD) was assessed via Intermodal Preferential Looking (IPL) to determine whether this population's difficulties with producing these morphemes extended to their comprehension. Method: Four-year-old participants were assessed twice, 4 months apart. They viewed a video that presented side-by-side ongoing and completed events paired with familiar verbs with past tense and progressive morphology. Their eye movements were recorded and coded offline; the IPL measures included percentage of looking time at, and latency of first look to, the matching scene. Spontaneous speech samples were also obtained and coded for number of words, past tense, and progressive inflections. Results: Relative to their baseline preferences, these 4-year-old children with ASD looked more quickly to and longer at the matching scene for both morphemes. Children who produced more words, including progressive and past morphemes, and those who performed better on standardized language assessments demonstrated better comprehension of "-ing". Conclusions: Overall, these children with ASD demonstrated consistent comprehension of grammatical aspect morphology; moreover, their degree of comprehension was found to correlate with spontaneous production and standardized test scores.