How can an Indirect Object Pronoun show possession?

Question

I was wondering how to say "I cut his hair" in Spanish. I thought it would be something along the lines of "Corté su pelo". However, when I went to Google Translate, what I got was:

Le corté el pelo

This would be literally translated as "(to) him I cut the hair", which is awkward-sounding but I get the point. What I don't get is how an ID pronoun can show posession. I read the canonical answer on this forum and apparently it's called "dativo posesivo", but I couldn't understand a single word it was saying. When I looked it up on Google, I can hardly find any reliable resources in English.

What is this phenomenon and can someone please go into detail about it? Why can't I say "Corté su pelo"? Is it because "su" is too general? What about the notorious "Me duele la cabeza" (me being an indirect object pronoun) (Literally, the head hurts me/To me the head hurts)? Is it grammatically correct to say "La cabeza me duele" (me being a direct object pronoun)?

Answer 1

Corté su pelo.

I seem to remember someone saying "Le corte su pelito," but in a more playful way. If you say "su pelo" without providing any additional information, then that sounds to me artificial, just like a dubbed movie or something that is wrong in my variety.

• Le corté su pelo lo mejor que pude.

• Le corto su pelo cada vez que me lo pide/cada vez que puedo.

• Le corto su pelo hace años.

The use of "su" without the "le" sounds unnatural for me, although the omission of the indirect object is grammatically correct. The possesive pronoun also includes a meaning of familiarity and closeness, signaling that the subject is well known and close to the clients.

• Le corto el pelo cuando tengo tiempo (better).

The dative possessive(DT) indicates who owns the body part or possession and it must appear with a definite article(DA)(el, la, los, las) instead of the possessive pronouns(PP)(my, mine, yours, his, hers, ours and theirs).

(Yo)[subject] corté (el)(DA) pelo[DO] (un tiempo)

Corté pelo en su/esa época.

The meaning of the verb cortar is realized in the subject Yo, the one who cuts someone's hair, but it can be omitted. But if, instead, there's no indirect object in this sentence, then it suggests that the person actually worked as a hairdresser for some time or for a time.

I'd say:

(Yo) Le(IO=a él/ella) corté el(DA) pelo(DO) => I cut his/her(PP) hair(DO) => I gave him/her(I0) a haircut(DO)

Le corta el pelo => Someone else cuts his/her hair.

Anyway, to me, this sentence wouldn't make much sense without a 'le.'

¡ME duele la cabeza! => A mí la cabeza duele(no one says it like that) => My(PP) head hurts.

In this case, just as the comment above says, "a mí" can be replaced by "me".

Answer 2

TL;DR: It doesn't show possession.

You can start with a canonical sentence like "escribí una carta a mi abuela" where you have the direct object "una carta" and the indirect object "a mi abuela". If we are already talking about your grandma, you can say "le escribí una carta", where "le" replaces "a mi abuela".

Then you can replace the verb with "cortar" and the direct object with "el pelo" to get "corté el pelo a mi abuela" or "le corté el pelo".

You can do the same exercise with "me duele la cabeza" canonicalizing it into "la cabeza duele a mi" (but never use this form!), where "la cabeza" is the subject, and "a mi" is the indirect object that can be replaced by "me".

So there's no need for a possessive form at all to understand whose head we are talking about.

As a matter of fact, the first time a Spanish speaker learns that you need to use a possessive form in English to refer to body parts it sounds awkward and it takes some time getting used to it.