In an investigation of discourse sensitivity, Catalan-speaking children aged 4 to 8 years were asked two different questions in a picture description task. One was a wide-focus question ("What is happening?"); the other was a narrow-focus question ("What is happening to 'the patient'?"). Children of all age groups displayed sensitivity to the various discourse constraints imposed by the two different questions, responding both with changes to word order and with changes in use of referential expressions. However, there was evidence of a developmental change between 4 and 5 years of age. The possible causes of this change are discussed.