Pigeon-like use of present simple.
"A mulher come, pois tem fome." Translation: The woman eats because she is hungry.
You will probably NEVER hear a native speaker say this sentence. Native speakers would say "The woman is eating because she's hungry" in almost every context. In general the constant use of the present simple tense is a weakness in Duolingo. The present simple is nearly always presented by Duolingo when native speakers would seldom, if ever use present simple in the context of the sentences given, rather they would use present continuous.
Simplifying the use of present tenses in English is a weakness in many language courses, and leads users of English as a foreign language to use the present simple in a pigeon-like fashion. In doing so, Duolingo, reinforces a bad habit with non-native English speakers.
Present simple indicates general facts, and customary or repeated actions.
"He walks to work everyday but today he is skiing."
Present continuous indicates current actions taking place "now", "at the moment". These temporal expressions test for the appropriate use of the present continuous tense. The word "now" and the present simple are incompatible. This is why "The woman eats because she is hungry." doesn't sound right. "she is hungry" implies "now".
And yet in Duolingo I have come across many sentences (for translation or accepted as translations) with the temporal/tense combination of "He eats now". Which to me as a native speaker sounds utterly non-native. It just isn't proper English and is misleading for the many language learners here who are not native speakers but are using English as an intermediary language.
Present continuous is awkward for non-native speakers, because many languages don't have such a tense. This might be a justification for replacing it in Duolingo too, if it weren't for the fact that good translations require it.
Sorry this got a bit long.
Agreed. It creates a misconception for native speakers as well. Duolingo should encourage the idea that when you say "She is eating" in English, you say "Ella come" in Spanish rather than using the gerund (English "-ing" endings, "ella está comiendo"). In my experience, many Spanish learners overuse gerunds when they come to learn them because the distinction isn't made clear and they are trying to translate too literally from English. As far as I know, other Romance languages are similar.
When I see a phrase like "Ella come" in a Duolingo lesson I translate it as "She eats" because I don't know if the more natural "She is eating" will be accepted. It seems sometimes the more "native" translation is accepted, sometimes only the literal one.
I can see why it's an issue because from the instructor's point of view, you want students to understand which part of speech is which, but that doesn't convey natural usage.
The translation of "She is eating" to standard Spanish is "Ella está comiendo", only in very rare case I would use "Ella come" (I am Spanish). There are some other areas where this distinction is not so, as it happens to be that American English and British English have some grammar differences.
I would like to say this original posting and the subsequent discussion is a very eloquent statement that outstrips all of the individual comments that I or others have made heretofore in the lessons. And I thank you, tylrmurphy for responding with that reassuring announcement. I know it may take time, but you guys are appreciated, at least by me.