Translation:Which country are you from?
https://www.yellowbridge.com/chinese/dictionary.php is pretty reliable. also, Google Translate shows the Chinese pinyin in small text underneath the Chinese characters when translating.
Personal perspective (I am a native Chinese speaker using duolingo just to see what its Chinese program is like): If you are meeting someone for the first time and want to ask them which country they are from, "你是哪国人？" is a bit too informal (because of 是) and slightly awkward-sounding. I recommend "你来自哪个国家？" , where 来自 means "come from" and 国家 means "country."
吗 "ma" is only for yes/no questions. So we could ask: 你是中国人吗？= Are you Chinese? (yes/no)
But this Duo sentence cannot be answered with yes/no. So instead, we use 哪 "na" (what/which). If you add a "ma" here, people will be confused because it would mean "Are you from which country?" :-)
'Which' is inviting you to pick from a choice of two or more. 'You can have meat or fish - which do you prefer?' 'What' implies what kind, of all the millions of possibilities. You answer the door to a stranger's knock and ask, 'What do you want?' What time is it - many choices. Which country - because looking at a map or list of the 150 countries in the world you would choose one. Also from the accent you guess they are American or British and ask which country. What is your nationality sounds like an interrogation at immigration.
I'm sorry if I'm being inappropriate, but since this skill is about countries and the 3 options given so far don't apply to me. I know my answer to this question would be 我是荷兰人 but I don't know the pinyin, tone or meaning of the individual characters which might come in handy with other words.
This is below level 1 lesson for learning Chinese expressions for nationality. Also, this would be the very first occurrence of word da3 in Duolingo Chinese course. Please, try to provide comments which would help us beginners to learn Chinese correctly, and stop showing better knowledge of that languague. The purpose of Duolingo is learning, not personal advertising.
Hello, I typed the exact same answer as the one displayed as the correct solution, yet it was not accepted. I was using Pinyin. I believe that the question mark sign was not the one the server expected. In the next attempt, I shall try using no question mark at all, or perhaps a 吗; I understand that sign indicates a question. As it stands, there must be a software error.