"An uncle is the brother of your father or your mother."
Translation:Un tío es el hermano de tu padre o de tu madre.
it's ok but we (spanish speakers) don't say all the words when we talk, we try to simplify or language, for logic we understand us, example, when we want to say yo quiero comer(i want to eat) we just say quiero comer, because yo(i) is included in the verb (yo quierO, tu quierES, nosotros quereMOS,etc) and so, we are all the time talking of the easiest way, in your phrase "Un tio es un hermano de tu padre o de tu madre", the word "de tu" is repeated 2 times, with the first time is enough, in fact you could say "un tio es un hermano de tu padre o madre" and we understand it. ;)
tú means "you" and tu means "your", is ok know it for a job and formal situations, and because is the correct way of write it, but i can say you, in fact, when we are writing something quickly, often we don't use the acents (´), really a few people use them in informal situations, because for the majority is laziness write them, or because they are ignorant people, when we are talking the acents are always pronounced, that's something learned since you were a child. the letter with the acent, is pronounced louder (á,é,í,ó,ú) just that.
i speak spanish, and no,mamá and papá are not childish ways for to say them, they are just informal ways, in fact is more probably we say mamá than madre, or papá than padre, because padre and madre are words with much respect, but they are also "fuertes"(strong, louder i don't know how to traslate it) ways in the actuality, for me and other people is weird and louder to say madre, and i prefer to say mamá, or even less informal we just say "ma" or "pa" but they are ways very informal, example: "ma te quiero mucho" or "pa me das dinero?" they're words widely used in mexico; for other people madre or padre is the correct way to say it, but often is wealthy people who talk of that way.and not always, papi or mami are childish words, for a child is ok but for a teenager is bad and embarrassing, but for an adult change the means and (just for adults) mami is a sexy girls (it's a vulgar way to say it) and papi the same than mami but in a man, but papi among men is used in mexico as joke just among men, a woman saying papi to a man is bad because is like seduce him, but if a man is not a friend of another man, saying papi is also bad, because is like a gay. spanish is very weird hahaha luck ;)
I don't know if you are trolling or not...
I'm gonna give a real answer nonetheless:
When you are asked to translate a sentence, you should not change the order of subjects. If you do, it could change the meaning of the sentence.
e.g. "Kiss Robin, then slap Angel!" has an entirely different meaning than "Kiss Angel, then slap Robin!"
Furthermore, changing the order of subjects could maintain the meaning of the original sentence, but it is still a different sentence, therefore should not be done.
e.g. "I love Robin and Angel" and "I love Angel and Robin" both have the same meaning, but still are different sentences.
This strict rule really does not depend on gender. Notice the unisex names that I've used.
It's not a language rule, it's a program rule. After all, it's not a human being checking your answers, it's a machine. A human checking your answers could be more lenient, and he could declare your answer as a right one, even though you changed the order of the subjects.