I suggest you beware this product. Not only the Company activates automatic renewals without consulting the user and without reminding that the expiration date is getting close, but the service rendered is fairly modest and is not worth the yearly 139.95 USD that they will surreptitiously charge you. Those charging policies are discouraged in the EU, but it appears that you may adopt predatory behaviours towards users in the US. Also, there is no trace of actual development in Grammarly. Contrarily to Windows, there is no way to make it work on any word processor for the Mac although the release of a plug-in for Word has been promised for a long time now. I believe it is fair to claim that Grammarly is merely a beautifully marketed package that overcharges you for a service with little R&D.
It may be useful to know that while they automatically charge you full price, they litter your inbox with offer discounts.