Five deaf infants with hearing parents enrolled in a parent-infant intervention program using total communication were videotaped during free play sessions with their parents. Videotapes of each child at program entry and program exit were analyzed. The functions of children's gestures, pointing responses, communicative vocalizations, and signs were coded using adaptations of M. Halliday's categories of language. The data supported Halliday's order of functional development. For all five children, the Instrumental, Regulatory, Interactional and Personal functions developed prior to the Heuristic, Imaginative, and Informative functions as predicted by Halliday's model. The present data, however, differed from Halliday's theory in that the development of the latter three functions was not necessarily concurrent with the development of syntax (i.e., combination of signs and/or gestures to form multi-sign language for the Imaginative, Heuristic and Informative functions). Imaginary pretend play episodes appeared to facilitate the use of both the Imaginative and Informative functions. This unexpected finding that the Information function appeared frequently in imaginary pretend play episodes was interpreted in terms of shared role-taking skills involved in imaginary pretend play and the Informative function and in terms of imaginary pretend play as one motivator for the use of language to convey new information unknown to the audience. (Author/CL)