How’s your grammar? Do you have a well-thumbed copy of Fowler’s Modern English Usage on your desk, or do you sprinkle apostrophes liberally in the hope some of them will land in the right places?

Microsoft Word, and most other word processors, will check your grammar and spelling if you ask it to, and this helps most people – we all make mistakes. But is Word’s grammar checking any good, or are there better tools available elsewhere?
I’ve tested three alternatives to see what they have to offer beyond Word’s built-in tools.
Pro Writing Aid
Pro Writing Aid is both a website and a Word add-in, which undertakes extensive grammar checks to locate common and not-so-common mistakes, and suggests improvements. You can either paste text into the website, or download the add-in and run checks directly from Word. The website doesn’t retain your text, but the remote processing means it takes a few seconds for the results to come back.
Highlights appear as changes to your document, so you won’t want to have Track changes turned on or you’ll be overwhelmed with amendments
Pro Writing Aid produces up to 19 different reports, covering issues including overused words, sentence length variation, complex words and “sticky” sentences (that is, sentences that contain a large number of “glue words” – short words the reader has to wade through to get to the meaning).
The Options panel lets you choose which reports to run; cutting down the number you run speeds up processing. A summary page shows which reports found problems, and from there you can drill down into the individual reports, which highlight any problems in different colours.
When editing in Word, these highlights appear as changes to your document, so you won’t want to have “Track changes” turned on or you’ll be overwhelmed with amendments. There’s a button on Pro Writing Aid’s toolbar to remove these highlights, but it overwrites any background colours you’ve used in your text.
Pro Writing Aid offers two levels of service: free and premium. The free service lets you use the website and many of the reports; premium, which costs $35 a year, adds seven extra reports and allows you to edit your text on the website or use the add-in (for Word 2007 and above).
There’s a 14-day free trial, plus a 14-day money-back guarantee. I found many of the reports useful and their presentation quite clear, but, as with Word’s grammar tools, you have to ignore many false positives.
Grammarly
Grammarly, like Pro Writing Aid, is both a website and a Word add-in, and it also sends your text to its website for checking without retaining it. Grammarly’s task pane inside Word is presented slightly better than that of Pro Writing Aid, and, once triggered, it checks your text as you type, indicating errors with green squiggles and adding suggestions to the right-click context menu.
It also offers full explanations and examples in its task pane, although the language it employs can be a little intimidating: when it says “Review this sentence for gerund/infinitive use”, I imagine those small, furry creatures with pointed noses and sharp teeth that Ronald Searle drew for the Molesworth books. Gerunds are verbs that are used as nouns, as in “I enjoy playing football”, where the subject is “I”, the verb is “enjoy” and “playing football” is the object, even though “playing” is the present participle of the verb “play”. Don’t confuse a gerund with a gerundive (the small furry creatures’ offspring), which in Latin is a verb used as an adjective.
The only option you can set in Grammarly is the writing style of your document, which can be general, business, academic, technical, creative or casual. This rather forces you to adapt to its way of writing, or ignore many “errors”. When set to general style, it shows a lot of blue underlines in your text where it finds possible synonyms, and, although it allows you to ignore these “mistakes”, it grates on me that these suggestions are presented as though they’re correcting an error. The task pane calls them “enhancements”, which is better. Switching to technical style turns off suggestions altogether.
Grammarly allows you to check your document for plagiarism, but I’m not sure how useful this is. Using a sequence of only seven words in your document that also occurs somewhere on the internet triggers this warning, which also suggests you insert a reference – in MLA, APA, or Chicago format – to the web text it has found, but this should be taken with a pinch of salt (oh, a cliché). It declares this column 4% plagiarised, since, among other things, it contains the phrase “using a mono-spaced font, such as Courier”, which Grammarly found in an article at codeproject.com about presenting programming code on websites.
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