 The phenomenon is subject to syntactic constraints. We have a good idea of the conditions under which we can fail to get bound readings, as characterized by binding theory. Thus, we know that binding is impossible in cross-over cases and cases where pronouns are ‘too close’ to their binder ((15) is a case of ‘weak crossover’, (16) is a case of ‘strong crossover’ and (17) is a violation of principle B of binding theory):