"Thank you! Welcome."
As explained in the notes here: https://www.duolingo.com/skill/ko/Alphabet-2/tips-and-notes
Some final consonants change their pronunciation depending on the starting consonant of the next syllable
In this case, when a final consonant ㅂ is followed by a ㄴ of the next syllable, ㅂ is pronounced as m
입니다 (im-ni-da) as opposed to ib-ni-da
It's not. If you answer something correctly but it doesn't accept the answer, the best thing to do is click the "report" button and it'll let you choose from several options, one of which is to say that your answer should be accepted (and it leaves a space to type in an explanation of needed).
Though it can take a while for the mods to change what's accepted from those reports, since they seem to be volunteers.
i know that in korean, certain words differ depending on the formality in use but i am having so much trouble with the 'thank you's' because there are so many of them. i understand that they are different ways to say thank you just differing formality wise but i have absolutely no idea how many ways there actually are to say thank you in a number count and in what sorts of scenarios i should use them in or what is more formal than what. :(
could anyone help a struggling duolingoian out?