Yolanda's blog

What  stands for  the thing(s) that/which:   I didn't understand  what  he was saying.  ( the things that  he was saying) Is this  what  you want?  ( the thing that  you want) What  is different from the other relative pronouns in that it does not refer back to a noun: I wrote my essay on  a photo which  was taken by Robert Capa.  ( which  refers to  a photo ) That's not  what  we agreed on.  ( what  does not refer to a noun) For this reason,  what  can't be used instead of  who, whom, whose, which  or  that  in relative clauses: I wrote my essay on  a photo  what  which  was taken by Robert Capa. When in doubt, replace  what  with  t he thing(s) that/which  and see if the sentence is still grammatically correct.

DEFINING RELATIVE CLAUSES NON-DEFINING RELATIVE CLAUSES