penMost of us like to think we’ve got the English language down pat. If your friends can understand you, then anyone can, right? True, but in business, the academe, and anywhere perceptions matter, you want to be more than understood—you want to impress. And that means flawless writing, among other things.

A sentence checker allows you to check your text for typos, wrong tenses, and more advanced errors like subjunctives and dangling participles. While you can find most of these concepts on the web and may even know them by heart, sometimes when you’re caught up in your writing these rules just slip you by. These programs are like a second pair of eyes, running over your words with a fresh perspective and a sharper ear for error.

Spelling and grammar checkers may be built into word processing programs such as Microsoft Word and OpenOffice, or may be purchased separately. The latter usually offers more functionality and will analyze your text more deeply. Built-in sentence checkers may be good enough for basic spelling checks, but if you want an “expert opinion” of sorts, a dedicated program may better suit your needs.

One thing that sets a good sentence checker apart from the mediocre is the ability to detect the writer’s voice. Basically, it takes into account the number of syllables and the length of your sentences, and uses an algorithm to see if your text is easy to read. It’s based on the concept that good writing uses simple words and a healthy mix of short and long sentences. While it won’t rewrite your text for you, it can prompt you to think twice about your word choices or rework sentences that beat around the bush a little too much.

Many checkers will also offer suggestions and explanations. For example, if you mix up “there” and “their,” a box might pop up with a little tutorial to help you along and help you avoid it in future writing. Of course, when you’re in a hurry this can be a little annoying, but you can always turn the feature off.

All that being said, grammar checkers can’t replace a pair of well-trained human eyes. Don’t rely on programs to perfect your writing for you. All they can do is stomp out the most glaring errors and maybe some less obvious ones. At the end of the day, good writing is the product of hard work, not a team of third-party programmers.