The Test of Preschool Vocabulary (TOPV) measures children’s ability to receive and express single words that represent all parts of speech and a variety of basic concepts (things, events, experiences, temporality, relational and substantive processes, and relative position). The words tested progress in order of difficulty from familiar words and concepts to less familiar ones. The TOPV has two subtests: Expressive Vocabulary and Receptive Vocabulary. Combine the results of the two to create a composite, the General Vocabulary Index.