When asked about grammar checkers, some teachers of English will immediately darken their eyes and pronounce them evil. No, this is not because they worry about losing their jobs to computers (English teachers will always be needed, certainly), but because they recognize the limitations of grammar checkers and fear that they make writers lazy or unthinking. Because my paper passed the grammar checker’s test, some think, it must be fine.

A simple demonstration will prove otherwise. Consider the following nonsense sentence:

Grammar checker tell this sentence just fine, even when longer made, even made more nonsense, full of grommets, so trust grammar checker little, worked harder instead, with eye for errors open, until grammar understood better, by you, who more politic than checker, which allow manifold mistake, all over place, indeed.

My grammar checker has no problem with this silly sentence; though any thinking reader would, and even assigns it a 12th grade reading level. Conversely, when I test sentences from one of our most lyrical works on science and nature, Loren Eiseley’s The Immense Journey  the grammar checker frequently wags its finger unhappily at the author, befuddled by his comma use, syntax, and sentence length. To put it plainly then, “Grammar checkers is stupid”—another sentence my checker accepts readily. This should be no surprise of course, in that grammar checkers merely match patterns derived from mechanical computations and offer suggestions with no understanding of context. In other words, they do not think. Since we do, we must and can learn to outperform them.

With these concerns in mind, I certainly do use and recommend grammar checkers to thinking writers, following these guidelines:

• Grammar checkers come with default settings, which can be changed to suit your needs. For instance, in my version of Word, I can go to “Tools” in my menu, choose “Options,” then choose “Spelling and Grammar,” and elect which options I wish to employ as my grammar checker crawls through my writing. Writing styles the checker monitors include such options as gender-specific words and passive voice, and the choices you elect in your settings influence the nature and number of suggestions made. You can also, for instance, invite the grammar checker to always suggest corrections or always ignore internet addresses. Look at your settings carefully and make choices for them that suit you as a writer, tinkering with your spelling and grammar options as needed.
• Grammar checkers are best at catching subject/verb agreement problems and unintentional verb tense shifts. Be sure you agree with the checker’s suggestions in these areas. You can brush up on these subjects in Chapter 1 of this manual.
• Grammar checkers are especially useful if you want to reduce your usage of passive voice, in that passive voice sentences are faithfully flagged. Keep in mind that passive voice is often acceptable (see “The Passive versus Active Voice Dilemma” in this manual), but use the grammar checker to help you favor the active voice.
• As you use your checker, always take a moment to note the explanation provided about the problem to be certain it fits the circumstances. For example, the grammar checker mislabels the following complete sentence as a fragment: “My papers, which I completed with my partners, Sue and James, received high marks.” Obviously, consult a style handbook to help you address uncertainties.
• My experience and research suggest that grammar checkers are least effective at discerning punctuation errors, and they are also especially poor at recognizing the proper use or absence of “a” and “the” (as shown by my example nonsense sentence earlier).
• Grammar checkers are particularly good at detecting certain kinds of typing errors, such as a space before a comma, an unintentionally repeated word, or a sentence with no end punctuation. Use them to help you catch such errors, which you can scan for visually even without actually proofreading a document.
• Keep in mind that, in a particular document, once you have accepted a sentence as error-free even though the grammar checker flagged it, it might not be challenged by the checker again, even after you do a bit of tinkering. This makes your thoughtful consideration of any suggestions made by the checker even more important.