I had a look at the Grammarly automated proofreader and personal grammar coach that claims to be the world's most accurate grammar checker, presumably in the automated category. The bad news is that those who want to post any text and expect it to be turned into perfect English will still have to wait for science fiction to become reality, but the good news is that it could be a very useful tool.
Basically, you paste a text into a box, choose the type of text and let it look for issues- and it does vary its searches according to the type. For instance, it spotted some first person usage in an academic text, which it wouldn't worry about in a general text.
Two of the tools I liked most were ones I wasn't expecting much of. I have always had my doubts about thesauruses, but the vocabulary suggestions it made did seem relevant- it offered address instead of tackle when it would fit and didn't just throw out random words of a similar meaning. The algorithms used are looking at words in the context and do often suggest good alternatives. With Grammarly, things are presented as alternatives and suggestions, leaving the decision to the user, but this tool struck me as an improvement on the standard thesaurus.
I also liked the plagiarism detector, which I had switched off at first, but once I rectified that, it showed its colours. I dropped sentences into long texts and it picked them up, and did not seem to slow the process up greatly. It caught something I pasted from a newspaper site of that day, so the service used is current. I also tried something from the Financial Times, which is behind a paywall, and it found the sentence I used quoted on a blog. This does suggest that the searches should be extended where possible to include paywall sites. However, it found a lot and found it quickly.
It also searches for hundreds of types of errors and makes suggestions, with explanations. I threw a text in from a British newspaper and it correctly spotted a run-on sentence and was good on commas after introductory phrases. I did see one suggestion that would have led to a possible error if I had followed it- it suggested that If + company name (singular) + were might be changed to was. However, it does make a lot of potentially useful suggestions, so for the keen writer, I think it could be a very useful tool, and I should emphasise that it doesn't say change this to that, but think about changing it.
I tried it out with increasingly difficult and varied types of text and as I moved into poetry, it struggled a bit, but it's not a tool to help Philip Larkin improve his verses, so that was cheating on my part. For a learner, I think this is a useful tool- it will go systematically through your text and try to help you with suggestions to improve it. Think about the suggestions, explore and test them, and you might find it useful too.
Disclosure: I was given time-limited free access to try Grammarly.
Any Grammarly adverts that appear on our site come via third party services like Google Adsense.