When to use "lo" and "le"?

Question

When to use 'lo' and 'le'? Someone told me that 'le' is used in Spain and 'lo' is used in Latín America.

Is there a rule on when to use them?

Answer 1

I think you are talking about "objeto directo & objeto indirecto" ("complemento directo & complemento indirecto").

As an example:

(Yo) Le di un regalo a Alberto / I gave a present to Alberto

Yo le di un regalo / I gave him a present (you know who)

Yo se lo di / I gave it to him (you know who and what you gave)

Another one:

Ella compró un coche / She bought a car

Ella lo compró / She bought it (you know what)

Ella compró un coche a Juan / She bought a car for Juan

Ella le compró un coche / She bought him a car

Ella se lo compró / She bought it for him

Answer 2

Indeed, there are rules, but it is important to distinguish between the rules that govern Standard Spanish (which should be used in formal communication) and informal or dialectal Spanish — which still have rules, just different from the standard.

In general, the following table explains when to use each of the object pronouns in third person:

     +------+------+ 
     | Dir. | Ind. |
+----+------+------+
| ♂  | lo   | le   |
| ♂♂ | los  | les  |
| ♀  | la   | le   |
| ♀♀ | las  | les  |
| ⚲  | lo   | le   |
+----+------+------+

That said, there are circumstances where this table might change slightly and some of the changes are actually considered, due to their very high level of use, acceptable in Standard Spanish.

• Le instead of lo/la
  This is found across the Spanish-speaking world for a number of different reasons. It is considered non-standard except in the following two exceptions:
  • When replacing a masculine and animate lo
  • When replacing lo/la that comes from Vd.
• Les instead of los
  Though the RAE recognizes that this is very common (especially by those that use le for lo), its usage is considered non-standard save for one exception:
  • When los/las stands for Vds.
• Lo instead of le/les
  This is always considered non-standard and not very common, but you do hear it once in a while. Mainly it's by people who speak Asturian/Leonese who use neuter lo for uncountable nouns in their language, or some Andean speakers whose native languages don't distinguish number/gender.
• La/las instead of le/les
  This is always considered non-standard and common primarily in central Spain. For these speakers, le/les is masculine only rather than ambiguous, and la/las become the feminine indirect object pronoun.

Answer 3

Your question is a bit general but you have a nice table on the RAE website that can help you:

RAE:pronombres átonos

So for the third person you have:

• Complemento directo masculino singular: lo/(le(leísmo))
• Complemento directo masculino plural: los
• Complemento directo femenino singular: la
• Complemento directo femenino plural: la
• Complemento directo o atributo neutro singular: lo
• Complemento directo o atributo neutro plural: -
• Complemento indirecto singular: le
• Complemento indirecto plural: les