This is an exercise from Duolingo. So the exercise asks to translate this sentence:
I ate pineapple everyday in Mexico.
And the correct answer is:
J'ai mangé de l'ananas tous les jours au Mexique.
There's two things that I don't understand about this sentence. First, why did we use the partitive article "de l'" instead of the indefinite articles "des" for the word "ananas". Like when we say: Je manges des/un fruit.
Plus, fruit is countable so it doesn't need a partitive article.
And in case if both me and Duolingo are correct, I wonder about the difference in meaning that "des" and "de l'" would make.
Second thing I don't understand is the usage of the passé composé instead of the imparfait; as it's a past habit.