This study examined the associations among child language competence during father-child play interactions, fathers' time spent volunteering in their preschool-age child's Head Start classroom over the course of one school year, amount of father play and reading to the child at home, and fathers' positive control during play. The sample of 68 primarily African-American and Hispanic low-income fathers were videotaped interacting normally with their children during two equal length activities: a free play situation with farm toys and a more 'academic-like' situation with wordless picture books and puzzles. These videotaped language samples were obtained at the beginning and end of the school year. The findings showed a significant positive association between child language competence at the end of the school year and fathers' reading to the child. Fathers' positive control behaviour during play was negatively associated with child language. (author abstract)