Over 13-weeks a control group (n=7) had all errors corrected, while an experimental group (n=9) had only article and sentence construction (run-on sentences, fragments, comma splices) errors corrected. Separating the two types of errors is essential, since the latter (representing grammar) are subject to theories of acquisition and the former (representing usage) are not. One-way analyses of variance ran on pretest versus posttest found no significant difference in either groups' article errors; however, the experimental group had significantly fewer sentence construction errors, implying that teachers should be sensitive to both the correction technique and error type; researchers should not combine the two error types in gathering data.