Ah thanks! (A general point: I notice that when you have to type an answer, sometimes you can make an error that is not picked up, either as a typo or as an error. That can be confusing as when you hesitate over a spelling or accent, then get marked right, you assume your answer was correct, when sometimes it isn't. I wondered whether this was one of those cases.)
I went through this lesson (phrases 1) before everything was updated and 'againn' was not introduced. I've finish both 'numbers' lessons and I still have not learned 'againn.' I think I can remember it now but do you know in which lesson this was introduced so that I may go back and review that lesson freguently until I have a better understanding of how it sounds and when it is used? Tapadh leibh!