What happens when you make a typo?
I make a decent amount of typos, so I was wondering, do they send any signals to Duolingo?
clarabouch is asking about something else. When you "peek", a signal is sent to Duo that you haven't mastered that word, so it makes you practise it more often (I only just learnt this). That doesn't happen with typos as far as I know, but perhaps it should, as Yamarrin says. It would help with use of accents and spelling.
If you type a word without an umlaut it will still accept the word, but will go "You have a typo!" and then explain your typo. Sometimes this is the case with other words, too; however, they can't be too lenient. They have to draw the line somewhere between typo and just not knowing how to spell the word. About the signal thing, though, I have no idea.