Demonstratives and Linguistic Interfaces

In writing up the section on use of kinship terms as pronouns in 3rd person contexts, I came across the following phenomenon, which, it seems to me, may have interesting implications for Minimalist conceptions of interfaces.

"Nguyễn Đ. H. (1997:43) mentions a third strategy for speakers of the Saigon dialect, namely, where the demonstrative element ấy is deleted and marked instead by a tone change on the kinship label itself. Nguyễn Đ. H. provides the following examples (observing also that this strategy cannot apply to words that bear inherent high tones such as chú or bác):

(5) a. bà ấy > bả ('she')
b. ông ấy > ổng ('hé)
c. cô ấy > cổ ('she')
d. anh ấy > ảnh ('he')
e. chị ấy > chỉ ('she')

f. thằng ấy > thẳng ('that guy, he')
g. thằng cha ấy > thằng chả ('that bloody guy')

Notice especially the contrast between the last two examples, which suggest that this operation is quite productive: tone-shift applies to the right-edge of the word. This would seem to indicate that the process is not purely lexicalized. On the other hand, it is lexically constrained, since elements bearing inherent high tones cannot be affected. It would also appear to have implications for Minimalist assumptions about the ways in which semantics and phonology can interact outside of narrow syntax (given that it is implausible to suppose that these phonetic properties enter into syntactic computations).

Briefly, then, this appears to be a morphophonological operation that is sensitive to phonological constraints, but which expresses a semantic property. Since the relevant phonetic property (the high tone which is realised as/changed to a low-rising tone when shifted to the left-adjacent segment) would seem to be syntactically inert, the question is how this phonetic change is able to affect interpretation unless semantics and phonology are able to interact independently of the syntactic computation?

Does anyone else think this is really a theoretical problem? or have I missed or misunderstood something obvious?

Does Vietnamese have expletives?

The normal assumption is that null-subject languages do not have expletive pronouns (i.e., pronouns used non-referentially, as, for example, in (1) and (2) below:

1. It remains to be seen whether John will come.
2. There has always been some controversy about her eligibility.

If Vietnamese is a null-subject language--and the typical absence of proforms in embedded clauses suggests this is the case--then it should not have expletives either. However, Phan Thi Huyen Trang (personal communication) draws attention to cases such as those in (3) and (4), in which, she suggests, the proform nó is non-referential, like English expletives:

3. Uống cho nó đã.
drink for it fill/quench
'Drink your fill (to quench your thirst)'

4. Tắm cái cho nó mát.
bath prt for it cool
'Take a bath to cool down'

These are interesting examples. However, at first glance, these do seem to be referential, although not in the sense of picking out participants in an event--which is the normal function of pronominal elements--but rather in referring to the Event/resulting situation itself. It may be more than coincidental that both of these examples show this element both embedded under cho: this is just where one might expect to see the event variable expressed (see section 5 of the grammar). In any case, it would be interesting to know whether these can also occur in the subject position of a matrix clause, and/or whether there are other such examples of a pro-form referring to situations rather than participants.