One of the reasons why people normally like Grammarly is because it is free. This is a free and accurate tool that you can use for correcting grammar. Grammar checking will also include the checking of spelling and punctuation so that you can have the perfect document each time that you need to submit.
If in case you cannot access Grammarly, you may use other free tools to check your Grammar, such as WhiteSmoke, Ginger, and ProWritingAid. There are some people who may actually prefer any of these other alternatives because of the other features that they offer, but for free services, you will normally get the basic services that Grammarly also offers.