This study was designed to examine how the form class and position of a word in a sentence influence the ability of primary-grade students to use available context to correctly guess an unknown word. Forty-three second-grade-level readers were asked to read orally four cloze passages that had been constructed from first-grade-level, basal reading textbooks. The responses of each subject were scored and tallied according to form class and sentence position for each deleted word. The proportions of correct guesses for each form class at each sentence position were computed and statistical tests were performed. Some of the results of this study were that deleted nouns and verbs in final sentence position were supplied in greater proportion than were nouns and verbs in medial position, which, in turn, were supplied in greater proportion than were nouns and verbs in initial position; that the positions of correct guesses depended heavily on both form class and sentence position; and that verbs were more difficult than nouns for second-grade-level readers to guess or predict. (Author/MKM)