The Different Types of Voices

English and a lot of the Indo-European languages are really loosey-goosey about things like this. Almost any case role can be the head of a relative clause in English or Latin or Greek or any of those. So we're used to a lot of flexibility there, but lots of languages are more uptight about this. And that's something that a lot of language don't do. That's way out there on the hierarchy of possibilities.