There is another sentence here on Duo where you have to use, "instituto," for high school to get the answer correct. Why isn't, "instituto," allowed to be translated as, "high school," for this question?
Also, spanishdict.com lists, "el instituto," as a translation for, "high school:"
d. el instituto (M) (Spain)
There are a thousand students in the high school.En el instituto hay mil estudiantes.
A native english speaker would very rarely say "to the high school." We would only say "to the high school" if we were talking about the building, just as in "to the institute" It is technically correct, but like many phrases offered by duolingo, only the more commonly used way is recognized. (references: native english speaker)
Unless you are in a small town, and there is only one high school. In that case, it's "goes to the high school". It is true, however, you're more likely to see "the" used in more complex sentences rather than less (so, adding a clause like "by the theater" or "in Port Richey" or whatever) , but there's nothing strange about using "the" here.
I got it wrong the first time because I put,
"My sister goes to an institution"
And it said the correct thing to say was,
"My sister goes to the institution"
So I put that the second time around and it STILL marked me wrong, but this time it said,
"My sister goes to a college."
Dude, I of course went to a library first, but they didn't have something about that /s (Joke's on me though, my university's library has – searching very superficially – at least ~80 works about that). In my Spanish class in 8th grade we translated "instituto" to "Gymnasium", a certain kind of school which is in no way comparable to the concept of a high school. I'd say words like that are so hard (or impossible) to translate literally because things like school systems are so different even inside countries. Why should a language have a word for something that has exactly no relevance in the region where it's spoken. For example, German doesn't have a word for "high school" because high schools just don't exist in Germany (or Switzerland or Austria or ,often forgotten, Liechtenstein. At least I think so.)
Yes, it does sound like one word runs into the other to me too. When one word ends in a vowel and the next word starts with a vowel, the two sound as if they are joined together. Here's a link to a native Spanish speaker talking about how he sometimes couldn't understand his mother when he was a child. He thought she was saying, "Nada más queso" but what she was really saying was, "Nada más que eso" (i.e. the vowel of the second to last word joined to the first vowel of the last word. I guess we have to listen very, very carefully to hope to be able to understand. :-) https://tinyurl.com/ybl9qzdh
Pfff... I was practicing not looking at the question so that once it was read in Spanish I could translate it from audio only, and having just done one of those "Write what you hear" questions before this, I just straight up retyped "Mi hermana va al instituto" right underneath the exact same statement lol
I would be careful about saying this... I suppose context is extremely important. I distinctly remember a government establishment in Callao, Peru called "El Instituto de Prostituto." I would not want to suggest that my sister goes there. Or anyone else's sister, for that matter.