I typed in "I eat orange" but correct answer was "I eat oranges" I think this sentence can be translated to "I eat orange" no?
Actually, the correct answer is "I eat orange", because "oranges" is plural, so if we translate "oranges" to Indonesian is "jeruk-jeruk" or "banyak jeruk".
It corrected me to say "I ate oranges". I did get it wrong, but the correction is different than here.
Does makan represent past and present?
Would it not be "Saya makan sebuah apel"... where's the "sebuah"... is it optional?
Yes, "sebuah" show that the thing is singular(?), but we rarely use it if we do an informal conversation