"I spoke to them in Spanish the whole time."
Translation:Yo les hablé en español todo el tiempo.
"Montones" is slangy Spanish that means "helps of" in the sense of "mountains of."
Also, the indirect object pronoun "les" (which is the indirect object pronoun that means "them") must always precede the predicate verb. Even when the indirect object is a noun, it still needs an indirect subject pronoun to come before the verb as well.
What is wrong with" Hable a ellos..." as an alternate? I looked it up and there doesn't seem to be any problem with saying it that way. "Hable a ellos" is understood as "I spoke to them". Anyway, i decided to put "Hable a ellos en espanol todo el tiempo" and it wasn't accepted.
Mishari, Gray_Roze is steering us in the right direction, I think. It seems to be either Les hablé a ellos en español todo el tiempo OR Hablé con ellos en español todo el tiempo.
In the first example, a ellos is an indirect object, so takes an indirect object pronoun. In the second example con ellos is a preposition + object, so does not take an indirect object pronoun.
NOTE: I'm another learner, not an expert. But, the correct ways to use hablar and conversar has been bothering me for a while and the above is what I've figured out. If I'm incorrect, I hope someone who is an expert will let us know!
EDIT, a month later: Unlike my usual posts, apparently this one is a little short, to the point of being incomplete! ;) I should have added something like;
Duo's demonstrations of hablar con seem to mean "to speak with" or "to have a conversation with." But, when he uses hablar a, it seems to mean more like "talked to" or, with the current prompt, "I spoke Spanish to them [but they spoke a different language]."
In other words, perhaps the difference in meaning is subtle, but Duo is showing us that there is a difference between hablar con and hablar a. And, hablar a requires an indirect object pronoun, hablar con does not.
Does this make sense?
It's not necessary in Spanish. "Les" is already an indirect object pronoun, so no preposition is needed. Other possibilites are to say "Hablé con ellos" (lit. "I spoke with them") or "Les hablé a ellos." In this case, "a ellos" is only added for emphasis, since it states the exact same thing as "les." However, "les" is still always necessary, and "a ellos" is a choice that can be added if you want to emphasize that you spoke to THEM as opposed to speaking to someone else.