mi-am curățat camera am curățat camera mea question : Ce ai facut azi dimineață? --Mi am curățat camera. Or you can answer "am curățat camera". The interest is the action. it will be weird if you use the other answer for the question I asked, unless you mean : I cleaned MY room, not HER'S " "Am curățat camera mea, nu a ei". Here you're insisting on the pronoun, "whose room you cleaned" .. I m not so good on grammar explanation. and My English is not that progressive neither. But I hope it was useful. ciao !

My full answer was too long, so I've cut out my argument for three cases in Romanian rather than five, but see here "https://en.wikipedia.org/wiki/Romanian_grammar" , section 1.3 Case. Now, the decision of which case to use, that depends on the function of the word in the sentence. Here we talk about subject, direct object, and indirect object. Consider this English sentence: "The woman gives the boy the ball." 1. Subject. Who is doing the giving, or who is doing the action of the verb? In this sentence, it's "the woman." The one doing the action of the verb is called the "subject" of the sentence. "The boy" or "the ball" is not doing the action of the verb, so those are not the subject. In Romanian, as in many European languages, for the subject of the sentence you use the nominative case form. 2. Direct object. Who or what receives the action of the verb? This is a little tricky. What she is giving is "the ball," which is therefore the direct object of the sentence. One might think that "the boy" receives the action of the verb, but that's not the situation here. If the woman picks up the boy and gives him to another person, then "the boy" receives the action of the verb, and is the direct object. In Romanian, as in many European languages, for the direct object of the sentence you use the accusative case form. 3. Indirect object. Who or what receives the direct object? It is "the boy" in this sentence. The one receiving the direct object is called the "indirect object." In Romanian, as in many European languages, for the indirect object of the sentence you use the dative case form. Similar for genitive case, where the general idea is "possession." Well, I've written a lot, maybe TMI. The same principle applies in German; there the issue is how to decide whether to use "der," "die," "das," "den," or "dem," or "des." I can give German examples, if you like. I'll leave it to someone else to answer your specific questions about Romanian. Hope this helps Garry

Dative is primarily used for indirect objects. I'll share an example with just second person singular. Suppose you are paying somone 50 lei for something. You would -not- say "te platesc 50 de lei" because the 50 lei is the actual thing being paid "to" the second person. So, you would say "Îți plătesc 50 de lei." Now let's pretend the second person didn't hear you correctly and acts like you said you are going to pay someone else. In English you might stress the word "you" in the same sentence and say "no, i'm paying YOU 50 lei." But to say the equivalent in Romanian you need tu use "ție" which is kind of like the stressed YOU. So in Romanian: Nu, îți plătesc 50 de lei ție. This is roughly equivalent to "I'm paying you the 50 lei TO YOU." Which in English sounds redundant but that's just how it is in Romanian.