AMERICAN SIGN LANGUAGE VERB AGREEMENT
Now that we understand how iconicity and conceptual metaphor function, and how they work together in signed languages, we are ready to tackle a core issue of ASL's grammar: verb agreement. We touched on this topic briefly in Chapter Five, while discussing space-for-space iconicity; it concerns how some ASL verbs move in space from an area representing one referent to an area representing another referent.
Most linguists talk about this phenomenon as if the two endpoints of the movement were all that mattered; they refer to it as “incorporation” of the referents' spatial locations into the verbs' movement patterns. I prefer to discuss it in terms of the verb's entire movement: In my analysis, the verb traces a path from one referent to the other that is specified by the verb's semantics.
In this discussion we will limit ourselves to frozen or lexicalized ASL verbs, and not examine classifier forms (which have their own iconic principles for incorporating movement). There are several different “systems” within ASL for determining how verbs move; all are highly iconic, and some are metaphorical as well. Some are based on the verb's semantics in a clear and obvious way, and others have taken on layers of conventionalized structure on top of the direct semantic motivation.