Grammarly is used for improving the quality of the written content by checking it for grammatical errors. The improvements can be made by considering the suggestions that focus on correctness, clarity, engagements, and delivery of sentences. Your spun copy of the content is judged on these parameters and an overall score is assigned for the write-up.
You can use the suggestions and tweak your content accordingly. However, this only corrects the content grammatically, and better alternatives for a word can be chosen based on the suggestions. It is to note that creating original content that is grammatically proofread by the tools can help businesses perform better in the digital platform.