I was looking back fondly over my past rejected job applications, when I came across a cover letter that I wrote to Grammarly in 2017, a grammar-checking app that came to prominence due to their aggressive YouTube advertising campaigns. They were advertising for a job for linguists, aimed in particular at people working on natural language processing. I used Grammarly for a few days, and had some fun devising tortuous variants of ungrammatical sentences to test what it could do. It does many things well, but it also makes bizarre mistakes that reveal that the app is not attempting to parse the sentences, or was doing so very superficially, and on which it is out-performed by existing parsers such as the Google Natural Language API or the Stanford Parser. I wrote these points up in a cover letter and sent it to them, which got me invited to an uninformative Skype interview and a polite rejection some time later. What follows is a brief summary of these points.