il mio vs. mio
What is the rule for using "il" or "la" in front of my?
Questo e il mio amico: This is my friend. questa e mia mamma: This is my mother.
Is it not needed when speaking of a specific person, thing?
Possessive adjectives (determiners) and pronouns always take the definite article (with one exception, see further):
il mio libro = my book → il mio (also quello mio ) = mine
la tua bicicletta = your bicycle → la tua (also quella tua ) = yours
i suoi amici = his / her friends → i suoi (also quelli suoi ) = his / hers
il nostro cane = our dog → il nostro (also quello nostro ) = ours
i vostri insegnanti = your teachers → i vostri (also quelli vostri ) = yours
la loro casa = your house → la loro (also quella loro ) = theirs
The only nouns before which possessive adjectives do not take the definite article are the common names of family members (i.e. relatives), when they are used in singular form. In this case, the definite article is dropped only before adjectives, not before pronouns:
padre = father → mio padre = my father ...but il mio = mine
madre = mother → tua madre = your mother ...but la tua = yours
fratello = brother → suo fratello = his/her brother ...but il suo = his/hers
sorella = sister → nostra sorella = our sister ...but la nostra = ours
figlio = son → vostro figlio = your son ...but il vostro = yours
Beware that the definite article is still required when:
① the 3rd person plural (adjective / pronoun) loro is used:
tua figlia = your daughter → la tua = yours
nostro zio = our uncle → il nostro = ours
la loro figlia = their daughter → la loro = theirs
il loro zio = their uncle → il loro = theirs
② the noun is used in plural form:
nostro nonno = our grandfather → il nostro = ours
tua cugina = your (female) cousin → la tua = yours
i nostri nonni = our grandparents → i nostri = ours
le tue cugine = your cousins → le tue = yours
③ the noun is a term of endearment:
padre = father
papà or babbo = dad [term of endearment]
mio padre, tuo padre = my father, your father → il nostro = ours
il mio papà, il tuo babbo = my dad, your dad → il nostro = ours
madre = mother
mamma = mum [term of endearment]
nostra madre = our mother → la nostra = ours
la nostra mamma = our mum → la nostra = ours
Especially in the north of Italy, but also in other areas of the country, many people tend to say mio papà instead of il mio papà , or sua mamma instead of la sua mamma. Strictly speaking, this is ungrammatical, but it is now so commonly heard that nobody would raise an issue about it.
Other nouns that differ from the English usage, in that they do not usually take a possessive adjective, are body parts, e.g. my head, your eyes, his hand, her leg, etc.
When they belong to a full sentence, i.e. when they act as a subject or a direct/indirect object, in Italian they usually turn into the head, the eyes, the hand, the leg, respectively, being understood that these parts belong to the same subject of the sentence.
I close my eyes in Italian turns into I close the eyes (which are obviously mine).
she raises her hand in Italian turns into she raises the hand (which is obviously hers).
Otherwise, an indirect object clitic pronoun is used:
I touch your hand in Italian turns into I touch the hand to you (to you is expressed by means of an indirect object clitic pronoun, placed before the verb).
Similar rules also apply to several nouns that in English usually take a possessive adjective, such as clothes (e.g. my shirt, your trowsers, etc.), personal belongings (my watch, your pen, etc.), vehicles (my bicycle, your car, etc.), in some cases to pets (my dog, your cat, etc.)
The full set of rules is somewhat complicated, as they depend on whether the noun is the subject, the direct object or the indirect object of the sentence.
I don't know whether Duolingo dedicates a specific lesson to this, but should this topic be brought up in the future I'll try to squeeze the rules into one post.
······[edited 31 Aug 2017]······
One part of the rules can be now found in this discussion:
You mentioned that the rule is "broken by adjectives"-- by that, do you mean this?
mia sorella → my sister
la mia grande sorella → my big (older) sister
-- there are other adjectives used to say this, I know...
mio marito → my husband
il mio nuovo marito → my new husband
(I'm having trouble coming up with adjectives that work with family members that you can't normally just add behind the noun instead... e.g. mia zia bella)
I forgot to mention this particular case in my previous note.
- If the adjective stands before the noun (this typically occurs with ordinal numerals), it forces the relative's common name to take an article :
mia moglie = my wife
la mia prima moglie = my first wife
mio figlio = my son
il mio secondo figlio = my second son
mia nipote = my niece (...or my grand-daughter)
una mia giovane nipote = a young niece of mine (...or a young grand-daughter)
- When adjectives follow the noun, they do not take a definite article. In this case, also a second noun (e.g. a working position) can sometimes act as an adjective:
mio fratello = my brother
mio fratello minore = my younger brother
mio fratello più piccolo = my younger brother [colloquial]
mia sorella = my sister
mia sorella maggiore = my elder sister
mia sorella più grande = my elder sister [colloquial]
mio cugino = my cousin
mio cugino avvocato = my cousin (who is a) lawyer
mia zia = my aunt
mia zia dentista = my aunt (who is a) dentist
When the adjective stands after the noun, as in this second set of examples, it can take an indefinite article, but not a definite one (some debate exists on this rule):
una mia sorella maggiore = one of my elder sisters ✱
un mio fratello minore = one of my younger brothers ✱
un mio cugino avvocato = a cousin of mine (who is a) lawyer
una mia zia dentista = an aunt of mine (who is a) dentist
✱ these would be usually rephrased as:
una delle mie sorelle maggiori
uno dei miei fratelli minori
Also the demonstrative quello can be used as an identifier for adjectives used after the relative's noun, but this sounds very colloquial (i.e. not to be used in a written text):
mio fratello quello alto = my tall brother (literally, 'my brother the tall one')
mia sorella quella giovane = my younger sister (literally, 'my sister the young one')
mio zio quello più anziano = my elder / eldest uncle (literally, 'my uncle the elder / eldest one')
mio nonno quello di Firenze = my grandfather from Florence (literally, 'my grandfather the one from Florence')
I realize that such intricate and whimsical rules might seem crazy, but that's the way it goes!
An excellent summary.
I wish that Duolingo reinforced the "body parts" exceptions more often, but here they accept both "il mio orecchio" and "l'orecchio", for "my ear", for example.
One assumes that you could use "mio/ mia" with your body parts for emphasis, I suppose?
This fits the case of body parts being the subject of the sentence, when the English verb is 'to be', e.g. my ear is clogged, your hands are cold, his hair is blond, etc..
In Italian, two constructions are possible:
- the most common one makes use of the verb avere ('to have') and sounds as a plain statement:
ho un orecchio ostruito = literally, I have a clogged ear
hai le mani fredde = literally, you have the cold hands
- the more emphatic construction runs in the same way as the English sentence, including the verb essere and the possessive adjective:
il mio orecchio è ostruito = my ear is clogged
This would be said to remark the ear condition, e.g. in reply to How come you can't hear well on that side? (but most people would still reply using the plain form).
Or - this sounds less likely - it could be said if a doctor asked Whose ear is clogged? (but in this case simply il mio would be enough).
le tue mani sono fredde = your hands are cold
This sounds rather emphatic. You would expect this sentence to be used in a film, or in a theatre play, rather than in everyday's speech.
Note that in the common construction (plain form), the owner of the body part is the subject of the sentence, the body part is the direct object of the verb avere, and the condition ('clogged', 'cold', etc) is an adjective referring to the direct object:
noi abbiamo le gambe stanche = we have weary legs → our legs are weary.
le gambe [direct object]
In the emphatic construction (which corresponds to the English one), instead, the body part becomes the subject, the owner is identified by means of the possessive adjective, and the condition is an adjectival predicate that follows the copula (i.e. the verb essere):
le nostre gambe sono stanche = our legs are weary
le nostre [possessive adjective]
stanche [adjectival predicate].
You wrote, "la loro casa = your house"
Is that correct? If it is, how do you say "their house" in Italian?
This is my friend= questo è mio amico/ questo è IL mio amico. This is my mother = questa è mia mamma/ questa è LA mia mamma.