Correct. When spoken you would use context and intonation to know if this was a question or statement. Russians often let tone rise at the end, much like English, or might put emphasis on the word мальчик if it was a question. In written: punctuation is the same in English and Russian. "Ты мальчик?" is "Are you a boy?" and "Ты мальчик." is "You are a boy." Note there is no "are". In PRESENT tense Russian almost always omits the verb "to be". It exists (it is "есть") but is not written or said.
You are correct but ты is only impolite in some situations. It is the 'informal' and вы is the 'formal'. You always use informal with family and good friends and young people with each other. Use formal with strangers and those you must show respect to such as a teacher, employer, official, or your colleagues until you are closer. Here it is ты because you can always use it with a little child, even if s/he is a stranger and always ты if you choose to talk aloud to your pet. As a foreigner I often used ты too quickly but no one seemed to mind. Also there is a phrase to ask if it's okay to be informal with someone: "Давайте на ты?" or "Shall we use 'thou'?".
Excellent explanation. I agree (native speaker). There is also such idiom as "выпить на брудершафт" ("drink bruderschaft"). After such (real or hypotetical) drinking it is considered that two persons may start using "ты". When somebody doesn't like that another person uses "ты" towards to him/her, she/he can say "мы с тобой/вами на брудершафт не пили, не тыкайте мне".
I like it! "We have not drunken to brudershaft/brotherhood" вами на брудершафт не пили. Can women use those idioms too, or would that be culturally wrong?
I find it interesting the German words (brudershaft) that are used in Russian (брудершафт). The other one I know is бутерброд ("butter bread"/sandwich). I always spell it wrong in Russian because it's spelled "Brot" not "Brod" in German. And my favorite story, I don't know if it is true, is that the word "bistro" in France and now America (a quick lunch cafe) came from "Быстро!" used when Russian soldiers were in France during the Second World War.
Can women use those idioms too, or would that be culturally wrong?
Yeah, it's not all that common expression overall, but there's nothing wrong with women using it. These days nobody really drinks to brudershaft anyway (ok, i did once, and with a fellow woman, but that was a joke, we were already long time friends by that point :) ), so many people don't even know what "брудершафт" actually means.
Honestly, you could translate it either way into English (in my opinion). Why? Because there is no such thing as the definite and indefinite article in Russian! Russian doesn't distinguish between 'the' and 'a/an'. They often distinguish specific objects with demonstrative pronouns (this/that = етот). The fact that duolingo limits translations to only accepting one option is the biggest critique I have with their program.
I am Russian and it is still hard to me to understand English articles but I reckon that in the situations when you need to use 'the' article you can also slightly modify the Russian sentence to make it clear. So if you are asking about some specific boy you can say
"Ты этот мальчик?"
"Ты тот мальчик?"
"Ты тот самый мальчик?"
A little hard to explain because we don't have the equivalent in English, but I'll try. Both ы and й are vowels and the lips are similar when saying them (closed vowels, like English 'ee'). But, one is a HARD vowel and one is a SOFT vowel. й is forward in the mouth and 'soft' or unstressed (like two English e's together 'ee'). ы is a 'hard' vowel and stressed. There is no similar sound in English. You make it in the back of the throat by flexing the epiglottis. Try this, leave your lips in the shape to say 'ee'. Now depress your tongue and focus on the back of your throat. Make the soft 'h' sound like in 'he'. Next put your voice behind it, don't say the "h" in "he", just the 'e' but keep the back of your throat open and make the sound back there like you do in "he". It will sound ugly at first. This is ы. Listen to a native Russian say it and it will get gradually more natural over time. --I was taught by my teacher, "say ee". Now pretend you were punched in the stomach while you were saying it.
"ч" you should hear in words. It equals sound "ch" (like chair or cheek) in English. But "ь" (the soft sign) and "ъ" (the hard sign) you will probably not hear. They are not letters that have sounds but rather a symbol that indicate how to pronounce the letters before them. Russian has "hard consonants" and "soft consonants" and they are difficult for a foreign speaker to hear or pronounce. In most cases, pronouncing a soft or hard consonant incorrectly will not make a problem in someone understanding you. But sometimes it will. "Мать" with a soft sign and spoken with a delicate "T" means = mother. "Мат" without a soft sign and said with a hard "T" means = filthy language, cuss words. Big difference! Any Russian word that has a "ь" or "ъ" in it will be considered incorrect spelling if you leave it out; i.e. spelling counts on duolingo.
"Ты, мальчик!" Yes. When writing change the punctuation and when speaking change the tone of your voice and it would work. If I could tell you how many times I was addressed as just "девочка" in Moscow, by total strangers. From a native I rarely heard "Ты" before it just: "hey, boy." "hey, girl." "girls". Casual Russian can be very economical with how many words are used to express an idea.
For some reason, I cannot remember how to spell мапьчик. It's extremely hard for me, and I'm not sure why. For some reason, the Cyrillic here just seems off, and it won't' stick. Any advice to make this spelling stick? I can't nearly break down into tears because I can't get it right and move on again.
I like to use my own tricks. I make up a story that relates to English or something else to help me remember. If I were to make a story to help me remember I might think..."well, 'mal' in Latin and in Spanish means 'bad' = мал. And this bad boy is being "cheeky" = чик. You want to tell him he is a bad, cheeky boy but you don't want to be too hard on him, so put a soft sign 'ь' in the middle = мальчик. Another hint: when you wrote the word above you used a п=P instead of an л=L. Maybe that is why? You wrote "map'cheek" instead of "mal'cheek" (in Cyrillic letters).