baltin argues against moving pro to spec-tp on this basis of so-called wanna contraction, illustrated in (15): placing pro between want and to would block the contraction of want+to into wanna. radford argues that an analysis that assigns an epp feature to infintival to (and so forces movement of pro to spec-tp), can still account for wanna: the latter can be achieved by having to cliticise onto the null complementizer ∅, and then having this [c-t] compound cliticise onto want.