I love Grammarly for FireFox! I am a person of (arguably) average or above intelligence with a large vocabulary who writes a lot. For reasons that would bore you, I never learned grammar well in school. The quality of grammar in my routine emails has increased dramatically since using Grammarly. Often I will take advantage of hints or explanations offered by Grammarly. Sometimes Grammarly make a recommendation I don't like and I ignore the recommendation...like using ellipses:). Grammarly on FoxFire has been a great resource to me.