Check QuesionsQ2 Main clauses in English, although it is preferable for them to be conceptualised
as CPs, are never introduced by an overt complementizer. Nevertheless, given that the
clause is interpreted either as declarative or interrogative, the presence of a non-overt
complementizer is justified. Finite declarative object clauses may or may not contain
an overt complementizer (Peter knew (that) Mary left) in line with the assumption that
they are CPs. Subordinate subject clauses, on the other hand, must contain an overt
complementizer (That Mary left surprised everyone).
Q3 Canonical structural realisation principles underlie the observation that certain
arguments are typically realised by certain structures. More specifically, theme
arguments are usually realised as DPs, location arguments as PPs and propositional
arguments as CPs. This way it may be claimed that verbs which select for a finite
declarative complement select for a CP rather than an IP. It must be noted that there
are exceptions to canonical structural realisation principles, i.e. there are non-canonical
realisations, e.g. when a nominal realises a goal argument which is usually realised by
a PP (e.g. home).
Q4 On one hand, there are certain verbs that take (non-finite) complement clauses
that do not contain complementizers (these also lack overt subjects, e.g. try, attempt,
promise, etc.), on the other hand, there are finite complement clauses which contain a
wh-phrase but not an overt complementizer (e.g. He didn’t know what to do). It is
assumed that in these cases there is a non-overt element in the complementizer
position.
Q5 It suggests that these elements occupy the same position, i.e. the C head
position.
Q6 In an embedded yes-no question the presence of the interrogative
complementizer determines the force of the clause, i.e. that it is interpreted as a
question. In an embedded wh-question there is no overt element occupying the C head
position and [Spec, CP] is occupied by the wh-element itself. Nevertheless, the clause
is interpreted as interrogative. Given assumptions about specifier-head agreement
observed elsewhere, it may be assumed that although the element in the C head
position is non-overt, it has the [+wh] feature and that is what the wh-element in the
[Spec, CP] position agrees with. Thus, it is necessary for the wh-element to appear in
the [Spec, CP] position to manifest this specifier-head agreement relationship. For this
reason a wh-element is seen as an operator necessary to promote the interpretation of a
clause. In echo-questions the wh-element remains in its base position and the structure
is not interpreted as a question, instead, it is interpreted as a device to provide missing
information. A wh-element is only interpreted as an operator if it has moved into the
[Spec, CP] position. In multiple wh-questions only one wh-element moves, the other
remains in situ. The interpretation of the non-moved wh-element as an operator
depends on the presence or absence of a moved wh-element in the same clause (The
interpretative principle: Interpret a wh-element as an operator if it is in [Spec, CP] or is
coindexed with a wh-element in [Spec, CP].).