This study used several measures to compare 40 toddlers with delays in expressive language and 40 children acquiring language normally. Findings indicated that children with small expressive vocabularies at 2 years of age are not different from their normally speaking peers in terms of hearing, history of ear infections, birth order, or pre- or peri-natal history. They do tend to come from families with a history of language or learning disorders. In addition, children with small expressive vocabularies: (1) appear to have subtle deficits in nonverbal problem solving despite having normal intelligence; (2) are very likely to show deficits in social maturity; (3) seem somewhat less motivated than normally speaking children to interact with others; (4) are perceived by their parents as being hyperactive and more difficult to manage than normal toddlers; and (5) show less phonological skill, in terms of syllable structures produced and number of different consonants used. Preliminary outcome data suggest that children with small vocabularies at 2 years of age are at moderate risk for language delay that continues until at least 3 years of age. They are at somewhat higher risk of articulation deficit at age 3. Social immaturity persists to this age. (RH)