In the present study, it was hypothesized that the proportion of open questions teachers ask during shared book reading would be directly and indirectly (through class aggregated mean length of utterance) related to children's vocabulary and would be directly and indirectly (through class aggregated mean length of children's utterance and vocabulary) related to children's narrative competence. A total of 7 early childhood teachers and 176 pupils participated in this study. Outcomes of mediation analyses revealed that the proportion of open questions was positively related to class aggregated mean length of children's utterance and vocabulary and negatively related to narrative competence. In addition, the proportion of open questions was indirectly and positively related to children's narrative competence, through class aggregated mean length of children's utterance. The results of this study indicate that the type of questions teachers ask during shared book reading is related to children's language competence.