Hi, I was wondering, how old do you have to be to become a moderator? And how active? Thank you. :)
Nobody has ever asked my age here.
I believe the main idea was to choose people who were active and helpful without even thinking of any special status. Activity is not the general number of comments but rather the amount of useful ideas, helpful answers and insights.
I have had some experience of being a moderator on other sites, and usually it is organized in a similar way to what has been done here: Administrators monitor the forum and find people who like to help and share useful information. Then they ask these people if they want to become moderators because they are already recognized and respected as helpful and realiable members. It does not usually work the other way around, i.e. when a person first wants to become a moderator and then tries to fulfill some "requirements".
The problem with trying to fulfil requirements is that it turns moderatorship into a one-time achievement. If you're trying to become a moderator like that then you need to ask yourself what would motivate you to act like a moderator once you've received the green M. The reason why the current moderators don't have to think about that question is because they were already acting in a way that was well suited for being a moderator.
Mallowigi's question "Why do you need it?" is a good one; why would you need to be able to delete comments or be more visible among other users? Helping others is something you can do no matter what status you have. Duolingo was built with cooperation in mind and I think everybody can contribute in her or his way. You might not get "official" recognition, but I'm sure there are still people who appreciate your help.