"Y esas ensaladas, ¿no las pruebas?"
Translation:And those salads, aren't you trying them?
Strictly speaking, placing the verb 'to be' after the subject (you are) makes it a statement, not a question. Yet it is common in rather informal colloquial speech to use intonation only to convey the question. One prominent example that is even taught to advanced students of English is expressing surprise by repeating your interlocutor's phrase with a question inflection while keeping the statement's grammar intact: "And then she threw it away!!!" "She threw it away?!?"
So yes, in this particular example the speaker may be expressing incredulity and using similarly informal speech. Yet Duo tends to lean toward formal use of grammar (even though this example is clearly a spoken phrase, which tends to be less formal), since there are many ways to convey ideas informally and they can really mix up and even be contradictory.
As far as your observation that there is no typo, you are absolutely correct. Duo in his limited ability used 'typo' as a synonym for a 'mistake'.
I'd agree with you except that not more than five sentences later in the same lesson, Duo gave a question with the exact same word order written as a question.
This is a good example of our trying to give reasons why the program accepts/rejects certain answers only to have other examples blow holes in the argument. Happens too often, unfortunately.
Yeah, in normal Spanish those final sounds 's' are often dropped. Having said that, if you heard (and I assume you did) 's' in 'las', then you should have figured out that 'esa ensalada' is, in fact, plural.
I realize that it sound hard, harsh and even unfair. But that is how Spanish works. It is especially tricky when we have to 'write what we hear' and we do not, in fact, hear it. Yet the word 'hear' in this context refers to our ability to hear as well as process what is being said. In my experience with Duo they always (or nearly always) give you enough information to figure out the correct answer.
Final observations: female voice is more likely to drop final 's' and 'n', so it is a good idea to check it on slow speed, if offered. Also both both voices (m and f) are computer-generated, not recordings of real people.
Very true, yet Duo uses it on numerous occasions. Perhaps it is more common in Spanish?
EDIT: it was pointed out by nEjh0qr4 that "the construction is as weird in Spanish as it is in English. But, Duo wants us to practice substituting las for ensaladas and has chosen this way to do it."
That is not entirely true. Technically, "Aren't you trying them?" is a question (see the auxiliary verb 'are' before subject 'you'). "You aren't trying them" is a statement, adding a question mark to it does not automatically make it a question. For more detail, please, read my other post in this thread.
"Best to play the audio slowly." Agreed. I often do so. "Duo blindsides you ..." I am not so sure. I would argue that Duo prepares us for real life. Imagine if Duo would always feature well-enunciated words and sentences, and then, thinking that we are ready, we encounter those "contractions and elisions in rapid speech" of native Spanish speakers. That would be 'blindsided'.
That's difficult. I applaud your work and can appreciate the difficulties. I'm working all combinations of English, Spanish, and German, only one of which I am fluent in. Working between two languages that aren't your native language is very difficult. I'm sure there has to be a better way to let Duolingo know that there is interest in your course combination; I'm pretty sure they won't see it here. Check out this FAQ to see how they recommend doing so: https://forum.duolingo.com/comment/15014194.