Is there always genitive after malo?
Yep. The same with other indefinite quantifiers like mnoho (many), hodně (a lot, lots of), několik (some, several) etc.
Why is "máte málo červených hrušek" wrong?
It is accepted, use "My answer should have been accepted" next time.
Thank you for your reply, a couple of suggestions that may be nice to pass on to the higher ups... stop using capital letters for the first word used when using the word bank , and try and find a color coding as to what sounds wierd to great
We are no Duolingo staff. You can discuss that youraself, in the main forum. The effect will be the same, I am afraid (nothing).
Můžu říct: "Máš trochu červených hrušek" ?
Yes, but the meaning is different (a few).
I think ''Máš několik červených hrušek.'' is also correct. Am I right?
No, that is "a few".