This study investigated the form of infinitival sentences produced by young children and their knowledge of the control properties of this sentence form. Twenty-five children between the ages of 3;7 and 5;4 participated in a story completion task designed to elicit infinitive sentences and in an act-out comprehension task. Although the infinitive form was productive for even the youngest children in this study, development of this form was not complete even for the five-year-olds, nor did any child demonstrate adult knowledge of control. In addition, two competing claims regarding order of acquisition (that of Limber, 1973, and Hyams, 1985) were evaluated.