Is Grammarly useful for English learners and non-native speakers?

Grammarly, that little browser extension that checks your writing, has been doing a lot of advertising recently. It seems it’s becoming quite a well-known tool. When I tell people about the app I’ve developed to help English learners improve their English, people often mention the similarities with Grammarly.

Grammarly aims to pick up errors with grammar, punctuation and style. It picks up all those typical mistakes that native English speakers make. For example, its instead of it’s, their instead of there and general typos.

But how good is it at correcting mistakes in English written by a non-native speaker? I did a few tests and the answer is — it’s not very good.

I wanted to write about this because I would hate for non-native speakers to be using Grammarly thinking that it’s leaving them with beautiful, correct English. It’s not. On average, Grammarly finds 40% of the errors in non-native English.

The other problem is, it occasionally highlights errors that are not, in fact, errors. This means an English learner can’t even rely on that 40% being true and accurate.

Below are a couple of examples of short texts written by non-native speakers. I’ve shown the mistakes highlighted by Grammarly and the genuine number of mistakes, after being checked by a human.

Texts checked by Grammarly in April 2019

I’m not aiming to criticise Grammarly for this. They don’t actually promote themselves as a tool for English learners, so I wouldn’t expect it to be an area they excel in. As a native speaker I’ve found it very useful. I downloaded it to do the research for this article but it has ended up catching a few typos that I accidentally made, so I’ve kept it!

What should non-native English speakers use?

I tested a few other online grammar checkers (listed below) and none were any better than Grammarly. In fact most were very poor at finding non-native speakers’ mistakes. I think the best one in the list below was paperrater.com.

Also not great — grammarcheck.me , languagetool.org , grammarcheck.net , polishmywriting.com , spellchecker.net , onlinecorrection.com , paperrater.com

A non-native English speaker’s best solution for getting correct English is, in fact, Google Translate. I put eight Spanish texts of 50 words each into Google Translate and translated them to English. I discovered that in a text of about 50 words there is on average one error. Not too bad!

Of course if you’re trying to learn English, it’s not recommended to always use Google Translate, but if you just want to end up with some accurate English (eg. for a job application) then Google Translate is your safest bet.

It is worth saying that I was testing translations from Spanish. I think the translation from less well-known languages may not be quite as good.

There’s one other very important thing to know for getting good results with Google Translate — you need to write the original text in complete sentences and with good punctuation. If you don’t, Google Translate gets confused and gives worse results.

Non-native speaker? Improve your English

If you’re a non-native speaker and you want to improve your English, try Go Correct. This is a Facebook Messenger app where you answer a question in English every day and have your reply corrected by a real, native English human. Over time you can see statistics about the types of mistakes you make most often, so you know which grammar points to improve on.