indirect objective pronoun

Question

how to answer ¿Tú visitas a tus abuelos? using indirect direct object pronoun ?

Accepted Answer

Hola Alyssa 
The verb visitar in Spanish is actually a transitive verb taking the direct object pronouns "lo, la, los, las" (not le, les, unless you are in a "leísta" part of Spain/Latin America).
So the answer to your question, Alyssa, would be:
Sí, los visito.
No, no los visito.
The fact that we do use the "a" when the direct pronoun mentions the person instead of using a pronoun is a bit confusing because we tend to associate the "a" with an indirect object, but the function of the "a" here is as John said the "personal a" in transitive verbs when the object is a person. 
Yo visito a mis abuelos.
Yo (subject)
visito (transitive verb)
a mis abuelos (direct object)
Therefore "Yo los visito".
Other verbs that might make you doubt are for example:

Conozco a Pedro.
I know Pedro.
Lo conozco.
I know him.
Tratan a Luisa muy bien.
They treat Luisa very well.
La tratan muy bien.
They treat her well.

All of them direct objects and direct object pronouns.
I hope this clarified it. 
visitar by RAE dictionary
Saludos
Inma

Answer

Hola Alyssa,

It would be good to get some help from Inma on this as well. It is a basic question but the fact that it is the verb "visitar" adds a bit of complexity (for me anyway).

I think the answer is "Sí / No les visito" which is "Yes / No I visit (to) them." Le (singular to him/her) and Les (plural to them) are indirect objects. I believe visitar is a verb that always takes an indirect object and doesn't take one of the direct objects: Lo, La, Los, Las. If your question is also about whether the personal "a" is required, I'm fairly sure that it isn't needed in this reply. I don't think there is a lesson on verbs that often take indirect object pronouns in Kwiziq, but this topic came up in night classes that I did eons ago and has stayed with me.

Saludos. John