Firefox Extensions to Grammar Explanations

LanguageTool is an extensive open-source proofreading tool designed for individuals and businesses, supporting a large number of languages. It offers crucial grammar, style, and spell checking capabilities across various platforms through browser extensions, desktop applications, and integrations.

Grammarly is a leading AI-powered writing assistant that helps users compose clear, effective, and mistake-free text in various contexts, from emails and documents to social media posts.