French help: pronom relatif lequel?In french class we are learning lequel and an example given was... 1. As-tu vu le film duquel il a parlé...

This translates to: 

"Have
you seen the movie about which he has spoken."

In French
and English we say "spoken about".  French do it more elegantly by putting "about"
before "spoken".  You still have to have the "about" word in the French question.  
It appears as "de" and attaches to "lequel". 

"parler de
..." 
and any verb that takes "de" will also appear as "duquel" when you say
"about which".

"avoir besoin de..." will do the same thing,
as well as other expressions/verbs that end with "de".