In this paper, we reconsider some of the processes that distinguish production and comprehension. In particular, we discuss the specific forms of thinking involved in each: "thinking for speaking" and "thinking for listening" (Black and Chiat, 2000; Slobin, 1996). We argue that thinking for speaking (or for any form of language output) crucially involves schematisation or "paring down" of conceptual information (Dipper, 1999), a process partly driven by the language system itself. Thinking for listening, on the other hand, involves an "enrichment" of skeletal conceptual information derived from the linguistic input, using pragmatic principles. Production and comprehension involve distinct forms of interaction between thought and language, and should not be characterised as a simple reversal of the same processes. This approach allows us to account for different patterns of production and comprehension in non-fluent aphasia, and predict some of the factors that facilitate processing for people with these language impairments.