Another question - why is this 'feumaidh tu', and not 'feumaidh thu' ?
Verb forms ending –dh (other than "bidh") get "tu" instead of "thu".
Or, if you don't like 'just because' as an answer, see my answer here..
ok - thanks!
if you do duo-lingo on the computer, or through internet (duolingo.com) you can choose tips when you want to start a lesson. There it gives explanation and grammar things....
My anglo mind would be so criss corssed if it weren't for the comments lol, thank you