il quale

il quale m (f la quale, m pl i quali, f pl le quali)

1. whom; which; after a preposition

   Synonym: cui

   l'uomo con il quale parlo ― the man to whom I speak

2. (rare) who; whom; which; that; subject or object

   Synonym: chi

   mia moglie, la quale è bella ― my wife, who is beautiful

   la mia macchina, la quale ho venduta ― my car, which I have sold

• Used instead of cui after numerals and other quantifiers + di:

  quattro dei quali ― four of which

• Sometimes used when the invariant alternatives che or cui are ambiguous with respect to gender or number:

  Giovanni e Claudia, ai quali avevi parlato ― Giovanni and Claudia, to both of whom you talked (plural and hence including all)

  Giovanni e Claudia, alla quale avevi parlato ― Giovanni and Claudia, to the latter of whom you talked (feminine singular and hence including only Claudia)

• Generally, use after a preposition is moderately common, while use as a subject or object is quite rare.