About Error Sheets, page 5

3. grammatical sophistication is required: Effective error sheet work requires not only a respect for grammar, it also requires grammatical knowledge and grammatical skill. In the first place, teachers using this method should have a fairly deep understanding of fundamental grammatical concepts. To illustrate this with an example: one of the most common, and most serious, errors ESL instructors have to deal with is faulty sentence punctuation. Correcting this mistake, in a superficial way, is a simple matter: in the case of a “run-on,” a matter of inserting a period, and perhaps removing a comma; in the case of a “fragment,” a matter of removing a period and perhaps inserting a comma. When this sort of error appears on an error sheet, however, that sort of correction may not be enough. It may be necessary — and it certainly will be necessary on occasion — to give a real explanation of why the error is an error. Such an explanation will almost certainly require a reference to the concept of a clause, a concept which can be properly understood only by contrast to the concepts of a sentence and a phrase... Moreover, in many cases a really satisfactory explanation of a punctuation error — one which will enable a student who habitually makes mistakes of this kind to detect and eliminate them — will often require reference to the distinction between finite and non-finite clauses.

The second way in which the use of the error detection method requires grammatical knowledge is this: to use error sheets effectively a teacher has to have not only a solid understanding of fundamental grammatical concepts but also the skill of applying that knowledge to a wide range of instances. The items on an error sheet do not come pre-processed and neatly labelled as do the items in a conventional grammar text. (And of course the fact that they do not is crucial to their value as error detection practice.) The fourth item in Error Sheet 1“A woman named Brenda. She charged murder” — can be taken as an example the need for skillful application of grammatical knowledge. Here the fact that the phrase, “a woman named Brenda,” is a fragment would be obvious to any teacher, as would the fact that the mistake could be corrected by inserting a period. However even a teacher who was theoretically familiar with the idea of a prepositional verb could easily miss the fact that that concept was the key to correcting and explaining the second obvious mistake in the item. Moreover, even a teacher who was theoretically familiar with the idea of a reduced adjective clause could easily fail to notice that the fragment contains such a clause and to point out to his or her students how the use of such an element can contribute to punctuation mistakes. (For example, a more sophisticated teacher might, if it seemed appropriate, point out that the fragment could, even though absurdly, be interpreted as a grammatical sentence.)