The third person Indirect Object Pronoun "le", particularly in Spanish-speaking countries in America (the continent), has traditionally been used in a redundant way, eventhough some could say this is a grammatical mistake.
It is used in a redundant way because by their own definition, pronouns (meaning, in place of the noun) are used to replace a noun, and therefore, if a pronoun is used, the noun should be omitted.
First of all, there are two types of object pronouns: direct and indirect, the former substitute direct complements (which receive the action of a verb), and the latter substitute indirect complements (which are benefited or affected from the action of the verb).
Let's start with a simple sentence (I will not include in it the "le" pronoun, though it should be there):
- el niño escribe un poema a su madre
Here,
"el niño" is the subject (the one performing the action)
"escribe" is the verb (which describes the action being done)
"un poema" is the direct complement (what receives the action of the verb)
"a su madre" is the indirect complement (who/what is being benefited from the action)
Let's first substitute the DC "un poema" with a DOP. We then get the following sentence:
- el niño lo escribe a su madre
Here, "lo" is the direct object pronoun because it replaces "un poema" (the direct complement).
Now let's just substitute the IC "a su madre" with an IOP. We now get the sentence:
- el niño le escribe un poema
Here "le" is the indirect object pronoun because it replaces "a su madre" (the indirect complement).
Given the last change, one could rightfully think that using "le" simultaneously with the indirect complement "a su madre" would be a mistake, but it is not, on the contrary, it's presence has traditionally been expected, what has been optional, is the indirect complement:
Currently, there seems to be a tendency in many sites (like Duolingo) and articles about this subject to avoid using it in a redundant way, so maybe there will come the time when it will be natural not to include it if the IC is present, but for the time being, at least in Mexico, it is the most common way of using it; to my ears it still sounds weird hearing "el padre compró una casa a su hija" instead of "el padre le compró una casa a su hija"
So yes, "ella le añade un programa nuevo a la computadora," at least to many of us, Spanish native speakers, is more than correct!
ㆍespañol ㆍgramática