The purpose of this study was to determine if syntactic maturity, as measured by T-unit length, clause length, and clauses per T-unit, and if the level of reading comprehension, as measured by cloze tests and a standardized reading test, of one group each of selected fifth, seventh, and ninth graders could be influenced by the students completing selected exercises in sentence-combining and embedding based on transformational grammar theory. Conclusions were that sentence-combining practice enabled students in all three grades to write more maturely than they did before the experiment. The practice helped students in all three grades equally well, and intelligence did not effect the results, since students with lower intelligence scores improved as did students with higher intelligence scores. The sentence-combining exercises, in the present form, did not help students to improve their reading comprehension. (Author/RB)