Clarity matters in business writing. Business documents are not always fascinating, and if your writing is oblique or cumbersome, you risk losing your readers midway through your text. VanWrite Sentence Aerobics is a $159 (free Web demo) add-in for Microsoft Word 2007 and 2010 that tries to analyze your text and offer constructive criticism, so you can revise the wording for clarity and brevity.

"Tries" is the operative word here, really: Before Sentence Aerobics can recommend changes, it must correctly parse the original language--but it didn't succeed at that preliminary task when dealing with the simple paragraph that I fed it. The paragraph read, in part:

"What could possibly go wrong? As it turns out, quite a bit. [...] Spanning Backup ($3 per month for regular Google accounts users) is a cloud backup service [...]"

In short, Sentence Aerobics' parsing is limited and error-prone, especially in dealing with idioms. Competing product StyleWriter Professional is less susceptible to such errors: It let the same exact paragraph slide with no recommendations, other than noting that one line has a high "glue word" count.

Once Sentence Aerobics finishes parsing your text, it offers recommendations. For the most part, its advice is sensible: Sentence Aerobics favors short, active sentences, and tries to trim prepositional phrases from the text. But since its parsing is often faulty, you end up with many recommendations that you can't implement. For instance, when I started a line with "It turns out this is not a bug," Sentence Aerobics told me that starting a sentence with the word it is not a good idea, since the reader may have trouble figuring what it refers to. But this generally sound advice again misses the mark due to poor parsing.

Sentence Aerobics integrates well with Microsoft Word 2010. Immediately after installing it, I had some trouble finding it in the interface, so I methodically clicked through the tabs until I found it as a button in the Review tab--a sensible spot. When you click the Sentence Aerobics button, a pane opens on the right side of the window. The upper portion of the pane shows the text that the software is currently analyzed, and the lower portion shows recommendations. You can change the font size if you like.

Color plays an important part in Sentence Aerobics: Strong action verbs are circled in green, subjects and verbs are highlighted in pink, prepositional phrases are written in gray, and some have yellow highlighting. This makes it easier to visually parse revisions, but the colors cannot be customized. Being color blind, I had to use Colorblind Assistant to figure out that the pink highlighting was indeed pink and not gray.

Sentence Aerobics bases its recommendations on writing guide called Target Editing, written by VanWrite founder Linda Vanderwold. An abridged 75-page PDF edition of the book, offered as a free extra with Sentence Aerobics, provides language-editing tips and concepts that you can use apart from a dedicated software application.

Sentence Aerobics is based on solid usage advice, and it integrates with Word 2010 better than StyleWriter does. But despite these bright points, the program's spotty language-parsing capabilities prevent it from being a truly useful language-editing tool for natural business writing.

Note: The Download button takes you to the vendor's site, where you can use a Web demo of the software. The Buy Full Version button takes you to another page at the vendor's site, where you can buy the software.

--Erez Zukerman