Grammarly will work with Microsoft Word. Below are instructions for how to download Grammarly for Microsoft Office via a Mac computer, though you can find the add-in buttons on a PC as well, and the process will be similar.
1. Open Microsoft Word
2. Select "Insert" -> "Add-ins" -> "Get Add-ins"
2. Search for "Grammarly" and select "Add"
4. You will be shown a new Grammarly tab in Word as well as a new button on the right to "Open Grammarly"
5. Select "Got it" and then click the Grammarly tab at the top. You will see that it's the same "Open Grammarly" button that's on the top right. Click "Open Grammarly"
6. You will notice a new window appear and you will be prompted to log in. If you have not already created a Grammarly account, select "Sign up"
Your account will be the same whether you are using Grammarly in Word or in your web browser. For help downloading the Grammarly extension for your web browser, see this article.