a raising verb is one that raises a component of a lower clause
into a higher clause. Consider
(1) John seemed to kiss Mary.
Logically, John isn't seeming, despite being the subject of the verb. Seeming isn't something you can do: what (1) is saying is equivalent to either of these:
(2) Seemingly, John kissed Mary.
(3) It seemed that John kissed Mary.
The standard analysis of this is to say that the raised component (the noun phrase 'John' in this example) originates as subject of the embedded clause, and there is an empty category (notated 'e') as subject of 'seemed', something like this:
(4) e seemed that [John kissed Mary].
That is, the verb 'seem' is marked in the lexicon as exceptional in that it doesn't have a semantic role for its subject. But syntactically, all verbs have to have subjects. There are two possible ways for 'seem' to get a subject: use an expletive 'it', or raise a subject from the embedded clause, giving these two possibilities:
(5) It seemed that John kissed Mary.
(6) Johni seemed [ti to kiss Mary].
In (6) the co-indexation is between 'John' and a trace, which is not pronounced but still occupies a grammatical position. The trace is what gets assigned the θ-role of the agent of the verb 'kiss'. This can't be marked for Case though, so the verb 'kiss' can't have subject agreement, which means it has to be in the infinitive 'to kiss'.
The adjective 'likely' causes raising in a similar way to the verb 'seem': It is likely that John will kiss Mary; John is likely to kiss Mary. Its synonym 'probable' does not: *John is probable to kiss Mary.
Raising verbs can also be transitive
, according to some theorists. One such is 'expect'. This has a θ-role of subject, the person doing the expecting, and its complement
can be either the person expected ('John expected the doctor'), or a clause
: what John expected was that the doctor would examine Mary. We say this as
(7) John expected the doctor to examine Mary.
But though 'the doctor' is on the surface the object of 'expect', it's not semantically the object the way it is in 'John expected the doctor'. Rather, 'the doctor' is underlyingly the subject of 'examine Mary', and is raised to the object of 'expect', leaving a co-indexed trace. Once more, the subordinate verb has to be infinitive, because the trace can't take Case and agree with it:
(8) John expected the doctori [ti to examine Mary].
However, this analysis is not the one adopted by the Chomskyan Principles and Parameters theory, which treats it differently, calling it Exceptional Case Marking. If this is raising, it is just raising from one position to an adjacent one, unlike with 'seems', where the subject clearly moves right across the verb. In P&P theory it is not clear what the receiving position should be: there isn't any good reason to suppose that 'expect' has an empty object position in front of its subordinate clause. Indeed, this would give it two complements, which is not allowed. So P&P theory says that raising doesn't occur, and the subject is case-marked as an object by the verb in the higher clause.
raising vs control
A raising predicate
like 'seems' is different from a control
predicate like 'hopes', although they are superficially alike:
(9) John seemed to kiss Mary.
(10) John hoped to kiss Mary.
The difference is that with raising there's only the one role for John, but with control there are two: John is hoping that John will kiss Mary. This is analysed as a different empty category, a pronoun called PRO ('big pro'), co-indexed with its antecedent:
(11) Johni hoped [PROi to kiss Mary].
The semantic roles are assigned within the lower clause, before raising takes anything out of it. So in particular use of the passive voice syntactically swaps around the roles but does not change them semantically:
(12) John expected the doctor to examine Mary.
(13) John expected Mary to be examined by the doctor.
This is different from control verbs, where there is an underlying direct object in the upper clause. The upper verb assigns a θ-role (semantic role) to its object:
(14) John persuaded the doctor to examine Mary.
(15) John persuaded Mary to be examined by the doctor.
These control verbs have two coindexed roles, one in the upper clause and one as subject of the lower clause:
(16) John persuaded the doctori [PROi to examine Mary].
(17) John persuaded Maryi [PROi to be examined by the doctor].