I know (because wikipedia told me) that there are 5 cases in Romanian ( nominative, genitive, dative, accusative, and vocative. I know Morphologically, the nominative and the accusative are identical in nouns; similarly, the genitive and the dative share the same form. Apparently, the vocative is less used as it is normally restricted to nouns designating people or things which are commonly addressed directly. Additionally, nouns in the vocative often borrow the nominative form even when there is a distinct vocative form available.
All this information is good but I still don't understand when each case is used. Please can someone explain in simple terms when each pf the cases is used. All of the explanations I have found online seem very complicated
nominative --- the subject (or predicate nominative) basically an " unaffected noun."
accusative --- a noun receiving the action of a verb. A direct object.
dative ---- the indirect object. When I mail YOU a letter, YOU are the indirect object.
genitive ----- possessive form. Think " 's " This one can be tricky because in English we turn nouns into adjectives without batting an eye. An example would be "three dog night." In that phrase, the type of night is a " three dog" and we just instinctually understand that. In other langs this might constitute a change of case/declension. Hope this helps.
A three dog night is an antiquated term referring to a very cold night, so cold that you would need three dogs in your bed (back when ppl used their hunting hounds as central heating). The vocative case is when you address someone directly -
Look [[pal]], I'm walking here!
Pal is in the vocative.
Vocative is a tough one to express in English but you use it mostly in informal situations when you address someone directly. It gives off a mood of direct familiarity or direct attention. In English it goes something like this:
"Ce putem face, Kevin(e)? Asta este."
"Oh Kevin, what can we do? That's how it is."
Notice that your name "Kevin(e)" ends in an "e". This means I am using the vocative case to express familiarity. You would almost never use this case with strangers. The only exception is when you are addressing a stranger directly in a contentious tone.
"Domnul(e)! Nu intelegeti ca nu mai avem acest telefon de vanzare?"
"Hey Sir! Don't you understand (formal) that we no longer have that phone for sale?"
You can see that the vocative case in this situation sets the tone in a contentious mood.
So you can either use the vocative when you want to express familiarity with someone you personally know, or when you want to address a stranger directly if you are in an argument with him. Oddly enough, even when you are in an argument with a stranger, you must still use formal language to address the stranger.
In either case, the vocative is considered informal way of communicating. Though you may still notice it from time to time which is good to see imo because Romanian is the only language to retain the vocative from Latin.
"tu mă iubești pe mine" - it usually sounds redundant
But there are some contexts where it totally makes sense, for instance the following conversation, between two lovers where person A is telling person B that he/she chooses to be with a third person instead
A: Il aleg pe el (I choose him)
B: Dar tu ma iubești pe mine (but you love me)
'pe mine' is added to emphasize that person A actually loves person B and that for person B persons' A decision makes no sense
Another context where this form is used is when making a declaration of love and you want to make it more profound.
Eu te iubesc pe tine, tu ma iubesti pe mine? (I love you, do you love me?)
Generally, the pronominal verbs - ex. 'mă așez'(I sit) are in Accusative, so you have to indicate what are you sitting on: mă așez pe scaun(I sit on the chair)
"Tu mă iubești pe mine" is thrice redundant, as 'iubești' indirectly indicates 2nd singular.
So it is sufficient to say 'mă iubești'. but that's spartan.
"Tu mă iubești pe mine" has profusion, clamour, emotion, ardour. It's a thrice great declaration. 777. xxx. 666.
Imagine a girl tells you: "You love me, not another". In Romanian: "Mă iubești pe mine, nu pe alta".
If you take out "pe mine" as redundant, you are left with "Mă iubești, nu pe alta". It sounds like a stub. It has no elegance, no flow, no articulation. It feels like she is a Spartan monk. A super efficient robot, who wastes no time with such matters. 2 words, 6 letters, is too much for her, jaja.
So when a girl tells you "Tu mă iubești pe mine" you know that is a very serious sentence. She's putting a lot of emphasis on what she's telling you. Thrice great. You. Love. Her. It's over. All your base are belong to her. jaja.
I have never learned Romanian, but am studying Czech for university, and it has 7 cases, 5 of which are shared with Romanian. Assuming that Romanian cases function in a similar way to Czech cases, here is a list of when they would be used.
Czech has the following cases: 1. Nominative 2. Genitive 3. Dative 4. Accusative 5. Vocative 6. Locative 7. Instrumental
Nominative is used as the standard form of all nouns. For example, "car", or in Czech, "auto". Or for names, form example, "Peter", or "Petr" in Czech. Nominative is also used for the question, "what/who is that?", and the answer, "that is a car/Peter". In Czech, "co/kdo je to?, and, "to je auto/Petr".
Genetive is used to express movement/position in relation to an object, such as "I'm going to the (inside of the) car" (Jdu do auta), or to say "without a car"/"except the car" (bez auta/kromě auta). In terms of names, you would use it to say "without Peter" (bez Petra), or "except Peter" (kromě Petra). Genitive can also be used to show possession through the expression "of (something)". For example, "the door of the car" (Dveře auta), or "Eva is the wife of Peter" (Eva je manželka Petra). In Czech, things that are alive are treated somewhat differently, so possessive forms of a noun are not consistent. For example, "The car's door" remains the same (Dveře auta), however, "Eva is Peter's wife", is somewhat different (Eva je Petrová manželka). It can be somewhat confusing.
Dative is used to express movement/position in relation to an object, with the difference being you don't go inside of the object. For example, "I'm going to (the door of the) car" (Jdu k autu). It is also used to express an action done by a direct object to an indirect object, such as in the sentence, "Peter is standing opposite of the car" (Petr stojí proti autu). For names, it is used either to say you are going to where a person is, "I'm going to Peter" (Jdu k Petrovi), or to say someone does something to someone else, "Eva gave Peter some food" (Eva dala Petrovi nějaké jídlo).
Accusative is used in the case of a direct action being done to an object. An example of this would be, "I see the car" (Vidím auto), or, "I have a car" (Mám auto). In the case of names, "I see Peter" (Vidím Petra), or, "We are looking for Peter" (Hledáme Petra).
Vocative is used whenever directly addressing an object, generally being used when talking to a living thing. You don't generally say, "Hey car, come here" (Hele auto, pojď sem), but for names, this is used any time you are speaking directly to someone. "Hey Peter, come here" (Hele Petře, pojď sem). The rest of the Czech cases aren't used in Romanian, but what the heck, I'll include them anyway.
Locative case is used whenever describing location, or when you say you are talking about something. So you would say, "I'm in the car" (Já jsem v autě), or to say, "We are talking about the car" (Mluvíme o autě). For names, it can be used for location on/in a person, or when talking about them. "The cat is laying on Peter" (Kočka leží na Petrovi), or, "we are talking about Peter" (Mluvíme o Petrovi).
Instrumental case is used to describe the means something is done with, certain forms of location, and to describe who/what someone has with them. For example, "I am going to work by car" (Jedu do práce autem), or, "The cat is under the car" (Kočka je pod autem)/ "the cat is between the car and the house" (Kočka je mezi autem a domem). For names, you can say, "I am with Peter" (Já jsem s Petrem), or, "The cat is between Peter and Eva" (Kočka je mezi Petrem a Evou).
By no means is this an all-inclusive list, and truthfully, I have no idea if the 5 cases Czech has in common with Romanian even function the same. But I'd imagine that it should function fairly close to this, and this should give you a good idea of how/why grammar cases are used. They are annoying at first, but after you become more familiar with them, you begin to appreciate the specificity and directness they allow when speaking. Best of luck, hope this was helpful!