Abstract The present study analyzed the effects of completing a dictogloss task on the development of English grammar (3rd person singular -s and articles) in a foreign language primary school context. Fifty 11–12 year-old elementary EFL Spanish learners worked on a dictogloss task individually, and in teacher-assigned dyads and small groups. Their grammar gains were measured by means of a pre- and post-dictogloss grammaticality judgment test. The analysis of the children’s languaging showed that the task encouraged learners in pairs and groups to equally focus on form, although not only on the target features, which did not improve. There was, however, a slight advantage of pairs over small groups and individuals. A number of research implications, drawn from these results, are discussed.