Hal's admissions interview (p. 4)
The yellow administrator’s usage is on the whole undistinguished, though I have to admit he’s made himself understood.
Context
The Dean of Admissions is reciting Hal's file at him, and Hal — mute, panicking, coached into stillness — is grading the man's usage like a composition instructor, with the grudging "made himself understood" as the passing mark. The joke lands hard later: making himself understood is exactly what Hal can no longer do. (Carlisle links Hal's usage-preoccupation to Wallace's own "Authority and American Usage" — his reading, recorded not adopted.)