Pretend you are writing a letter to an alien coming down to earth. Write what would see if they were here?

I will write about what the earths like, and would you stay to earth. Because I think it will be fun with aliens on are earth. We can teach the aliens how to speak english. And I will write about, aliens home, what's it look like, and the aliens will teach us, how to built the future. It will need a good help of the aliens. And they will protect us.