"You have to be ashamed."
Translation:Вам должно быть стыдно.
The hints are not wrong here. It's just that sometimes a different translation of a phrase requires a different translation of the whole sentence for it to make sense, and hints can't help you with that.
"Ты должен" has to be followed by a verb, whereas "стыдно" is an adverb. So you'd have to rephrase: "ты должен стыдиться", which is grammatically correct but not as idiomatic. "Стыдиться" is a verb that means "to be ashamed".
And if we use the verb "быть" after "ты должен" we'd get "ты должен быть" which is "you have to be", so the hint is technically correct again but doesn't work with "стыдно" because it's a different sentence structure. You'd need to translate "ashamed" as a participle instead of an adverb which is "стыдящийся" (or "стыдящимся" because it would have to be in the instrumental case after "быть"), but "ты должен быть стыдящимся" is an incredibly clumsy sentence that no Russian, except for inept translators from English, would ever use.
No Nathaniel, I don't think it would match the person saying it -- it's not an adjective describing the person (like 'I am necessary to do something'...or 'you are necessary to do something' if we think that должен would agree with the gender of the person being spoken to).
Rather the sentence translates into 'It is necessary for me to do something', which is why тебе takes the dative case (i.e. for you) and why должно will not change; It's a predicate in this sentence, "It is necessary for you to be ashamed".
Huh. You know, only after reading Connor's comment, it occurs to me.. This is the only example I can think of where, rather than "should" or "have to", the otherwise arguably antiquated "ought" is the English word most commonly used:
"You ought to be ashamed."
Because it's the way Russian grammar works. Sorry, I don't know what answer you expect. We never omit быть as an infinitive.
«Вам должны́» means 'someone owes something to you'. «Вы должны́» means you should/ need/ must / owe something.
No, I think you're getting confused.
Try think of the sentence as "It is necessary for you to be ashamed."
- 'it' is the subject (omitted in Russian along with 'is', as быть isn't needed in the present tense),
- должно is the predicate expression (i.e. the "adverb" that goes with 'is')
- тебе (for you) is the indirect object (hence dative)
- to be ashamed / быть стыдно --> what's necessary for you, infinite tense.
I hope it's easier to analyse it this way if we change the English sentence like I've done here! DuoLingo is looking for a semantically correct translation that would actually be used in English, hence "You should be ashamed!" is clearly better, despite more tricky to analyse to understand the Russian version.
Well...because it (as an adverb) is playing the role of a predicate (something that goes with 'to be' like 'you are nice' or 'I am old'). In English you would always use some form of 'to be'. The same applies to Russian except for the present tense where you omit it. Here, we're in the infinite tense (both English and Russian), so 'to be' it is.
Быть или не быть...to quote Hamlet.
Or 'Бить или не бить' if you're considering whether to beat/hit somebody or not... ;-)