Il en a laissé prendre à ses enfants

[alan gould]

The rule for this construction says that with "faire" and sometimes also with "laisser," the subject of the verb that follows can be preceded by "à" or "par."  

The first example is "Il a fait taper la lettre à (or "par") la secretaire -- He had the secretary type the letter. 

The second example is "Il en a laissé prendre à ses enfants" -- He let his children have some.  

I can probably learn to do the first sentence correctly when I encounter something similar.   The second one is harder for me.  If I try to express this sentence in the future, I'm sure I will do something more like "Il a laissé ses enfants en prendre."  I would think that this would be understood and not even sound odd.      

[Chantal Savignat]

"Il en a laissé prendre à ses enfants"  hum,  it's not really nice,  this sounds a bit odd.

I prefer "Il a laissé ses enfants en prendre." it would be better understood than the first.

"laisser"  + "à" with the subject, I know one way with some words like "le  soin" or others  in the middle of the sentence : "Il a laissé à ses enfants le soin d'écrire la lettre." But it's already a formal way.

"faire" + "à" + the subject is better.

[Peter En]

Just a question-what is the function of "le soin"? is it just something that follows "laisser"  + "à"

[alan gould]

I only knew it as "care" but I looked it up and they have the exact expression "laisser...." -- "to leave it to somebody to do something"

[Chantal Savignat]

"laisser le soin" is an expression that means "to entrust" or "to give the responsability", it's the reason why the end of the sentence has been changed.

using an expression "laisser" + a noun like "laisser le soin", "laisser la responsabilité" is the way to have "laisser" + "à" and the words following "à" as subject of the action verb.