Construction tasks involve numerous demanding sub-tasks such as creating a mental model of the goal object and integrating the object parts into this model. For this purpose object parts need to be assigned a function within the overall structure. In this paper we examine the linguistic represen- tation of this process. Participants were given 16 object parts to assemble without a manual, and were asked to think aloud while doing so. Depending on condition they were not given any specific information, or told that the goal object was a dollhouse, or shown a picture of the dollhouse. In a second study, participants were asked to instruct a partner to assemble the dollhouse. Results of our linguistic analysis of think-aloud data and instructions reveal three strategies of assigning function to objects, one of which occurred exclu- sively in instructions. With less specific information about the goal object, functions were more often assigned explicitly. In these cases function tended to relate to the overall structure (e.g. ‘house’) rather than to structural parts (e.g. ‘wall’).