Therapy depends on present levels of performance and severity. If non verbal and unable to imitate: introduce signs/gestures to ease frustration for family, while beginning imitation tasks (starting with single sounds, CVCV or CV words/approximations, or gestural imitation as is appropriate for individual child). As approximations/imitation is emerging, begin to introduce some functional vocabulary. I generally use Kauffman's materials and PROMPT combination, as well as other techniques in therapy.