Infinitives can modify direct objects in Spanish???
I was watching a DVD earlier today and came across the following construction: Lo harán hablar. The English was They will make him talk! I would have thought that the Spanish should have been Harán que hable.
Did I see that right? Is hablar modifying LO in the Spanish sentence?
In the past 3 years of studying Spanish, I do not recall ever once encountering such a construction. In fact, I had assumed such a thing to be impossible in Spanish. Does anyone else have any information on this use of infinitive? Does this pattern have a technical, grammatical name? I actually like it and find it rather efficient, rather English-like, but what are the limits on this?
(I asked this earlier on another post, but decided to make a separate thread of it.)
10 Answers
Does this pattern have a technical, grammatical name?
Yes, it is a causative construction, and it only happens with verbs of influence (eg. hacer) and perception (eg. ver).
Please, note that "hacerán" is not a correct form in any case.
It might be "Lo harán hablar"
By the way, "hablar" in your sentence does not modify the subject (or any other noun) it's a kind of a complement of the verb (hacer). As Lazarus points out, a causative construction (you really need to think of 'hacer' and 'hablar' as working together. In some languages (e.g. Japanese) this causative construction is conveyed by a specific form of the verb, thus 'hanasu' ='to speak' and 'hanaseru'='to cause someone to speak'.
I would suggest that you substitute force, obligate, cause or some other synonym for make and see if that changes your perspective.
They are forcing him to dance.
....to sing
....to cry
...to forget
....to yield
With the verb make we don't include the "to".
Lo hacerán harán hablar. Does it look more reasonable now?
from our dictionary hacer
voy a hacer teñir este vestido -> I'm going to have this dress dyed
Do you see the similarity in this sentence?
substitute lo for este vestido.
Lo voy a hacer teñir.
Look familiar?
I want to say this construction in English is acceptable. To make someone to do something. "They made him to explain it." "They made him to go to the store." Or as my friends like to say, kind of as in inside joke, "Making the others to be jealous."
Le harán hablar. Does it look more reasonable now?
No, unfortunately, it still does not look reasonable to me because from the beginning of my experience with Spanish, it has seemed that verb forms (except the past participle) could not apply to anything other than the subject of the sentence. I am quite shocked to see an infinitive modifying a direct object in Spanish. I'm quite used to English doing this sort of thing.
I am fine with "They will make him talk / They will force him to talk." I am shocked to see "Lo harán hablar." I have always been under the impression that if you wanted a verb to apply to something other than the subject, then you needed to use que and introduce another full clause with a new subject and verb. Thus, I would have translated it as Harán que hable. However, I have no reason to doubt the Spanish dub in the DVD. I will happily accept this new (new to me) construction. I am just..in shock...is all.
And, I don't remember seeing such a construction before. I don't know if this means it is a rare usage for infinitives or if it means that my Spanish skills are only just now advanced enough to notice it.
Sorry about the whole "hacerán" thing, guys. I think I have corrected all instances to the "harán." XD
from our dictionary hacer
voy a hacer teñir este vestido -> I'm going to have this dress dyed
Do you see the similarity in this sentence?
substitute lo for este vestido.
Lo voy a hacer teñir.
Look familiar?
Okay, thanks for the dictionary link because I found this in there:
14. (ser causa de)
- hacer que alguien haga algo -> to make somebody do something
- has hecho que se enfadara -> you've made him angry
- me hizo reír -> it made me laugh
It looks like it is just an alternate form of harán que hable.
So, I wonder if it is limited to direct objects of hacer and only can be used in the sense of make someone/something do something or, as Mokay indicates in another thread, it can be used in many different situations.
With the verb make we don't include the "to".
Soccer! dunce corner for life!!! 
Cmon, make somebody to do something!!!
Tal caso, web, es
Le harán hablar, hacerán is incorrect. (hacer is irregular)
Me hizo subirle todas las maletas.
Me hizo llorar.
