Drozd notes that Crain & Thornton's view of children's processing capacities (namely that they are the same as those of adults) is inconsistent both with the more widely held view that there are at least quantitative differences between the performance systems of children and adults, and with what is known about the acquisition of many grammatical phenomena. There is, I believe, an additional consideration that must be brought to bear here: there are highly suggestive parallels among children acquiring their first language, adults acquiring a second language, and Broca's (agrammatic) aphasics with respect to the comprehension of patterns that involve comparatively heavy demands on the processor. These parallels not only seem to confirm that children's processing resources are initially compromised, they point to the possibility of a greater role for processing in understanding grammatical development.