What would make the difference between "The men eat papaya" and "The man eats papayas"? Would that be "Người đàn ông ăn những đu đủ"?
you'll need a classifier here, either trái or quả: "người đàn ông ăn những trái đu đủ."
I'm almost sure that this means "those who are men eat papaya", but it's kind of confusing.
An issue with some of these sentences (I found another with the same issue) is that they can be both full sentences or noun clauses. In this case, this sentence can be "the men eat papaya" or "the men who eat papaya." See my comment above about the papaya eating men staying home. The actual Vietnamese changes not at all, only has words added to form an entirely different sentence.
Why is it "papaya" not "papayas"? Because in the previous sentence "Những đuá tre ăn tào." is "eat apples" not "apple"?
Yep, here's a more useful one:
"Tôi ăn cây thường xuyên". :)
In case you're wondering what that means, it means "I usually/often eat the stick" which means "I often get beaten with a stick". lol
True, but Duolingo is also to teach grammar, not just potentially useful sentences.
You could, though. Just add a few words for fun.
Những người đàn ông ăn đu đủ phải ở nhà.
All the men who eat papaya have to stay home.
to have the continuous tense you would need to add the present marker đang.
những người đàn ông đang ăn đu đủ.