AbstractThis paper proposes a method for the top‐down utilization of the linguistic constraints in the speed understanding system. In the proposed method, the syntactic constraint is represented by the context‐free grammar, and the semantic constraint is represented by the semantic marker and the case frame. The two kinds of constraints are integrated by using the definite clause grammar, which is an extension of the context‐free grammar. Based on the resulting representation, the word predictor program described by Prolog is generated by a mechanical transformation procedure. The left‐to‐right parsing scheme is assumed as the control. As the parser, a combination of top‐down and bottom‐up methods is adopted to parse utterances. This eliminates the problem in which the procedure falls in an infinite loop if a recursive rule exists, which has been serious in the traditional word predictor. The method was applied to a task, and its validity was verified. The average branching factor of the task was estimated by a simulation.