Is it correct to say, “All of the cars had been stolen”? Or should I write, “All the cars had been stolen”?
According to The Chicago Manual of Style, we should delete the ‘of’ whenever possible. (All the cars had been stolen.)
There are exceptions, however. (It seems that there are always exceptions when it comes to the English language!)
Use ‘all of’ when it precedes:
So . . . All my exes live in Texas. (There is no need for ‘of.’) Please give all of them my condolences. All of George Strait’s exes live in Texas.