Placement of double pronouns in passé composé followed by infinitif.

Question

J'ai vu des oiseaux passer dans le ciel.J'y en ai vu passer J'en ai vu y passerWhich of the above is right?

Accepted Answer

Hi Jaya,
It would be -
J'en ai vu y passer
But in truth, you would probably say -
J'en ai vu passer dans le ciel 
because 'dans le ciel' is too vast a place to be replaced by 'y' and you lose meaning.
Chris - En because it replaces des 
otherwise, your answer replaces les oiseaux
Hope this helps!

Answer

Replaycing les oiseaux (les) and dans le ciel (y):Je les ai vus y passer. -- I saw them passing by there.J'en ai vu y passer. -- I saw them passing by there. (But this time it refers to specific birds of an implied group of birds.) Maybe the translation "I saw some of them pass by there." is more correct in this instance.

Answer

Merci Cécile! My doubt is cleared.  J'en ai vu y passer.  Chris, "des oiseaux" can be replaced only by en, not by les I guess.