I don't use facebook, how can I invite friends via email?
You do not "invite". Just send them the link to this site and they'll have to register and wait...
This is from the times where new users could join only by invitation. Now it is open for all. By "wait" I meant "wait for invitation" (limited invitation quota every month coming from DuoLIngo).
ok well.. I guess they changed it now 'cause below your friends list it says "invite by email"
you need to go to Home, then scroll down till you see on the right "Send Invite" then type the person's email.
I've sent 2 personal invites and the invites have not been received. Anyone else experience same?