Advances in Role and Reference Grammar

116 ROBERT D. VAN VALIN, JR.

such as modality should "weak obligation" is shared by all cores, whereas it

is not shared in core coordination. This is also illustrated in the Turkish

examples in Figure 32 (=108a) and Figure 33 (=108b). This follows from

the point made at the beginning of this section, namely, that the defining

feature of cosubordination in contrast to coordination is the shared

operators at the level of juncture. Hence the crucial contrast is a feature of

the operator rather than the constituent projection. It should be noted that

in many languages there are no obligatory nuclear or core operators, unlike

the obligatory IF clausal operator. Therefore these structural differences in

the operator projection will be manifested in nuclear and core cosubordina­

tion, even if there is no overt operator at the relevant level in a particular

sentence.