Thread:Cdragon13/@comment-25297120-20141028063732

Hi there,

It may be the first time I post on your Message Wall. As far as I know, you are the one who reads many books and loves writing. I think it is the time when I need your help. Would you mind to correct/to clarify some grammar points in badge articles?

There are some retired badges on Khan Academy. We are using Simple Past tense to describe the progress. Please read the article and let me know if there is any grammar error. We are discussing how to write this sentence properly "To earn this badge, users had to..." or "To have earned this badge, users had to...". Please let me know which one is better? To keep articles neutral, I have to use some repetitive words: "users", "this badge", "the badge", "exercises"... Besides, my vocabulary is not rich enough. Do you have any idea to improve this kind of writing? 
 * About past tense (e.g. Team Beta: Challenge Champion)
 * About
 * About repetitive words (e.g. Da Vinci)