Translation:It is the biggest island in the country.
bigger plus grand
the biggest le plus grand
don't forget agreement either
I doubt it. That would translate to "This island is the biggest in the country."
Here's a hint for deciphering what you heard. Look at what you wrote down: find the subject and the verb. If you see that the verb is missing in what you wrote (as in this case), listen again more carefully to identify the verb and rewrite the sentence in proper French. Although Duo sometimes offers short phrases or just a few words, this focused-listening approach will often help you to hear better.
why don't we use la plus grand before l'ile as per the BANGS rule ??
It can be used either before or after the noun. Both versions are accepted.
Could this also be expressed as C'est la plus grande île dans le/au pays? This grammar feels clunky to me, and doesn't seem to flow in my mind :/
You could say "C'est la plus grande île dans le pays" but I don't think that is accepted in the new version of the French tree being tested. Unfortunately, moderators are not permitted to edit it.
Clearly this is a part of the difference in prepositions between languages that is very challenging between French and English. Of the three suggested DL translations to English, NONE of them mentioned "in". And yet "in" is the suggested answer? Just trying to help........
If you expect a literal "in" = "dans" approach to translating, you will run headlong into many idiomatic differences between the languages. It is not that "of the country" is wrong, but it is more common to say "in the country". As to Duo's translations, sometimes they may be tweaked in ways to suggest a more literal translation and by so doing "make it easier" to translate back to French. While this approach has some logic behind it, it is misguided to think that you have to change how English is used in order to facilitate the translation back to French.