Practice, practice, practice. Save your students’ errors and use them to make an editing practice sheet, just working on this one thing. It’s a common error, partly because we all hear and see subject-verb disagreement so much—on television and radio, and even in newspaper copy. Another problem is that some nouns look and sound singular—few, most, several—even though they are plural. To make the problem worse, sentence subjects sometimes hide out. For instance, could your students find the subjects in these sentences?