 Similarly, in (9), PRO is a specified subject for "we", thus blocking disjoint reference, so that "we" can corefer with "us" in the non-finite clause.In (8), PRO is not a specified subject for "us", allowing "each" movement from "us" to "other"; similarly in (10), disjoint reference between "us" in the matrix clause and "us" in the non-finite clause is not blocked by a specified subject, because "us" in the matrix clause controls PRO.Similar examples hold for subject control verbs like "persuade"