If Grammarly had any idea how loudly I advise people not to entrust their data to Grammarly, I imagine they would regret the surely hundreds or thousands of dollars they spent showing me Grammarly ads.
Until I discovered the magic of uBlock, a visit to YouTube always prompted a blizzard of Grammarly ads. I could never understand the premise of these clips, in which native speakers of English - specifically, university students and young white-collar workers - were shown having to use the software to help them to write emails.
Protip: if you spent nearly two decades in full-time education but somehow remain unable to construct a proper written sentence in your native language... your parents should ask for their money back.
Re: Your pro-tip: I suspect their ad is correctly targeted, and you're not fully considering why people might use their service.
Anecdotally, the individuals I work with who use Grammarly are among the most proficient speakers and writers. They can write fine, but they'd prefer to spend time writing rather than editing and Grammarly picks up the slack.
> Protip: if you spent nearly two decades in full-time education but somehow remain unable to construct a proper written sentence in your native language... your parents should ask for their money back.
In principle, I agree with you. But long ago, I worked as a copy editor, and can tell you that time in school has a weak correlation with the ability to construct a proper written sentence.
But no, nothing I've seen from Grammarly suggests that it would be much help.
From [1], "Adjectives modify nouns; adverbs modify verbs, ..." - so though you're right that both sentences are grammatical, I think a lot of styles would have a problem with "a proper written sentence" since what you actually mean to say is "a properly written sentence" (unless you make it clear that you speak of "proper sentences", probably).
Protip: if you spent nearly two decades in full-time education but somehow remain unable to construct a proper written sentence in your native language... your parents should ask for their money back.