it is real French. they sound the same in real life. only by context you can tell the difference. so this kind of ambiguous sentences shouldn't be used here. I get them wrong cause there is no context and I can't tell if it is singular or plural. :(
You can tell the difference in the audio if you listen carefully. Le is pronounced "luh" and Les sounds like "lay". There is a clear difference. "Real life" may not necessarily be the case, but the audio in this software is not ambiguous.
Not in good French. The definite article "les" is required here. Sometimes if you have a long list of things, 4-5 or more nouns together, you can drop the articles. Otherwise, keep the articles with their nouns.
It is not a question of which sounds more natural to you, the computer marks it as incorrect if the order of the words is reversed. Please try to translation as closely as possible to the original phrase and keep the same order of the words.
A human teacher could probably see that you understood the sentence but mixed up the order. A computer is less smart and the first deviation from the entered answer will cause the computer to count it as wrong.
Do we still use "sont" if it was a singular girl and a singular boy? For example, la fille et le garçon sont calmes? If so, then how do we know if the subject was singular or plural to use "le" or "les"?
You would still use "sont" even with one girl and one boy because in total there are two people. You would know whether it was more than one girl or one boy by listening to the article. La fille et le garçon sont calmes. La and le sound very different from les.
i just don't seem to hear the difference between 'les' and 'le' ever i always have to rely on the verb to tell me which one it was...and this didn't work for this question coz with the girls involved, either 'le garçon' or 'les garçons' will give a 'sont'