No reason, just no one thought about it. Maybe it sounds a bit less... polite? sophisticated? Anyway, it was reported by one of the moderators and should be accepted soon.
'weżcie dwa' am I right in thinking this is 3rd person plural of this sentence? What would 3rd person singular be . . . . weżesz dwa?? Or have I miss understand and this is a command structure?
Yes, this is imperative, a 'command structure'.
"Weźcie" (it's Ź and not Ż, an 'accent' and not a dot) is 2nd person plural. "Weź" would be 2nd person singular.
Imperative for 3rd person is constructed differently and I don't think it's taught in this course, although frankly, it's a lot simpler. You use the word "Niech" and then use a form for 3rd person.
So you'd have "On weźmie" (He will take) and "Oni wezmą" (They will take), and then "Niech on weźmie" (Let him take - this would be the imperative?) and "Niech oni wezmą" (Let them take).
(It's "WILL take" because it's perfective, and perfective verbs do not have present tense.)
My concern is with "dwoje". Doesn't this mean " two people" like Russian "двое", which cannot be used for 2 inanimate objects? Shouldn't "dwa" be used in this particular context?
Not necessarily. Dwoje/troje/czworo ... can be used to denote:
- group of people of different gender;
- kids, young animals (here, it can be perceived as bookish)
- plurale tantum (pluralia tantum) - verb that has only plural number: like: spodnie (trousers/pangs), okulary (glasses), skrzypce (violin), zajęcia (hm, courses at university?)