Performing an action and concurrently describing it creates possibilities for observing how speech and action are synchronized and mutually shape each other. The results to be described show that iconicity is an organizing principle of motion control — actions are performed in relation to speech in such a way as to create an image of the meaning in part. Four English-speaking subjects described their goal-directed actions, step by step, as they assembled a small aquarium. Among the factors observed to have an impact on synchrony are, in speech, perfectivity (imperfective or perfective) and, in action, the logical form of the action (Vendler’s activities, accomplishments and achievements). These factors must be considered jointly. Depending on the logical form, speakers placed the linguistic center (‘L-Center’) of the description — the satellite or a preposition in the case of activities and accomplishments, the verb itself in the case of achievements — in such a way as to recreate the aspectual viewpoint concurrently encoded in speech. Imperfective aspect was indexed with progressive verbs. L-Centers with this aspect were placed inside or prior to the completion of the action. Perfective aspect was indexed with non-progressive verbs. L-Centers of this kind were placed after the action. In addition, the actions themselves were longer with imperfective aspect, even when the same logical form of action was involved. Non-functional movements were added to goal-directed actions to help create the imperfective aspect, and both speech and action timing were adjusted to create the aspectual viewpoint. These patterns are reminiscent of the perfectivity differences in gesture performance described by S. Duncan (2003) for Mandarin and English. Motor movements adapt to language in a way similar to gestures. Theoretically, there is a three-sided synchrony of two forms of motor action (speech, manual manipulation) and the logical form of the action. The theoretical discussion considers two ramifications: the implications for ‘cognitive being’ of building aspect into action, which suggests a mechanism of the mutual shaping of speech and action; and the brain organization that might underlie the three-sided synchrony, with emphasis on the role of BA 44 and BA 45 (‘mirror neurons’), collectively ‘Broca’s Area’, in the orchestration of actions under some meaning (actions of gesture, manipulation, and speech). These areas include language but are broader in function than the classical term ‘language area’ implies.