"Qui est responsable d'avoir laissé la fenêtre ouverte ?"
Traduction :Who is responsible for leaving the window open?
More correct. 'Who is responsible for leaving the window open' rather sounds like we are asking whose responsibility this job is, rather than who has done it which is what is required here.
Yes. I think "leaving" is what I'd normally say here, but "having left" is correct too.
I don't understand. ..to leaving "partir" no? To let "laisser" no? Please explain to me. Thank you very much.
To leave can mean "to go away" (partir) or to not change something, to "leave" it unchanged (laisser).
" for leaving " rather than " to leave or to have leaving " I don't understand
j'ai encore du mal en français à comprendre cet emploi ?