To take an example from Chomsky (Knowledge (1986), p. 8), any native speaker of English knows that them can be interpreted as being coreferential to (i.e. referring to the same set of individuals as) the men in (5) (a) below, but not in (5) (b): (5) (a) I wonder who the men expected to see them (b) The men expected to see them
Source: wiktionary