The distinction between "you're" and "your" might not look like much to some, but confusing the two can deeply annoy those of us who value good grammar. While we do understand that learning a second language is a hard job, these comma usage mistakes or spelling errors happen even to the native speakers. That, in turn, can either make the recipient laugh or miss your message entirely. Following the rules of English grammar makes your texts clearer and more respectable.
Learning the difference between homophones like "horde" and "hoard" will also help you stay out of trouble with the grammar police. We suggest checking out this list of grammar jokes, so you know how to stay on their good side!