"I am Chinese."
I'm sure you've had your question answered already since it's been 5 months. But to any future readers who are picking up the language, kanji are Chinese characters that often have both on'yomi (Chinese "imported" readings, modified to fit Japanese sounds) and kun'yomi (native Japanese readings). For 中, the imported Chinese reading (on'yomi) is ちゅう and the native Japanese reading (kun'yomi) is なか.
There are specific grammar rules for when to use which reading, with many exceptions. In order to keep things simple, there are a few basic rules of thumb follow to help you guess the reading. When you see a kanji by itself or attached to hiragana to form a word, the native Japanese reading (kun'yomi) will be used. Kanji that are paired with other kanji in the same word (jukugo word) often use the imported Chinese reading (on'yomi). There are certain exceptions such as counting numbers (which use on'yomi), and body parts (which use kun'yomi), etc. You'll learn them as you study kanji in more detail. I suggest trying out WaniKani to learn different kanji and their readings in much more detail.
Interestingly enough, Duolingo seems to have a consistency error with the 中 kanji in specific because you always see the ちゅう reading with the なか sound played. Do report this as the wrong sound being played if you come across it.
- "I am Japanese" = 日本
- "I am Chinese" = 中国
Both of them use 人, but you might be thinking of the sentence 日本しゅっしんです。which means a different thing. 出身【しゅっしん】means "a person's origin", so this sentence means "I am from Japan". (Being "from Japan" is not the same as being "Japanese")
"desu" is a copula used in polite speaking. It means "to be" and note that verbs in Japanese are put at the end of the sentence. In Japanese, you can drop the subject if it's clear what the subject is. So here "Watashi wa chuugokujin desu" becomes "chuugokujin desu". Now, "desu" is here just to express politeness. If you want to sound casual, you can drop the "desu". So then "chuugokujin desu" (polite form) becomes "chuugokujin" (casual form). Remember you should always be polite to people older than you, to people who have a higher social status than you and to elders. It would also be a good idea to be polite to people who you just met.
Different languages not always have the same structure to express the same meaning. Thinking a の might be necessary, is logical from the standpoint of the English language (and some other languages as well) but Japanse does not use it in this context (there will be similar examples in the course later on, assuming they are covered on this site).
No, it's Kanji and Hiragana.
中国 (ちゅごく) is the Kanji for China (literally translating to middle country, referring to its location). 中 is the Kanji meaning middle, and 国 is the Kanji meaning country.
人 (じん) is the Kanji meaning "a person" (don't confuse its use with (出身 / しゅっしん, which means "to be from"). Using 人 after a country (China in this case) translates to China person, meaning the subject is Chinese.
That means 中国人 translates to Chinese (person).
です translates to "is" in this case. Since we're not given the context of the conversation, it's implied that you're speaking about yourself.
It is very commonly left to context, as are many things in Japanese. There is no real difference between the two sentences you have there, especially if the listener is aware that you are a learner (/non-native speaker). Among native speakers (i.e. not me), I imagine adding 私は, especially if you do it repeatedly in quick succession, makes you seem somewhat self-centered or needy, since you constantly want to make sure the conversation about yourself (even if it already is).
This is the 8th lesson in level 2 and I've only gone over John, Maria and Tanaka of America, China & Japan as origin or home country. WHY MUST WE GO THROUGH 15 LESSONS OF THE SAME THING? Why can't we learn other names or countries yet? Other introductory attributes? My goodness. If level 3 starts these same lessons over again, I'm shedding my completionist trait.
Calm down. Learning anything, particularly a new language, requires repetition. Some would argue 15 lessons of the same thing is not enough. Others may find learning a language much more difficult than you and take comfort in a slow pace which builds their confidence. For others still, this pace is too fast. Maybe they don't want to learn hiragana, katakana and kanji all at once; it's too much!
Besides, this is one course made for many different people, so why do you expect it to cater to your exact learning speed? I mean, good for you that you want to learn more stuff, but do you realize how self-absorbed you sound? My goodness.
How is everyone typing the, "中国"? I can get the "中" with 'chuu' kana on my keyboard, but not the, "国." Any advice?
edit: I've found that if I type in "naka koku' or, "naka kuni' that the correct kana will appear. But why? I know it's been somewhat said above, but I still don't totally get the whole "read" and "spoken" (kunyomi & onyomi) concept.