[matrix] matrix - general: inserting chunks into the type hierarchy

[Gertrud Faasz]

this is the second of a number of questions on the type hierarchy of the
grammar matrix, each we will post separately, for they touch different
issues.

question no. 2 concerns chunks

Northern Sotho verbs are written disjunctively i.e. morphemes carrying
morphosyntactic information on verbstems are usually preceding the stem
as stand-alone units. Concerning the object noun phrase(s) usually
succeeding the stem, one can see the following phenomenon:

the "ordinary case":

 <NP monna> <VP <V o reka/> <NP dipuku>> - (the) man he buys books

The object noun phrase can be replaced by an object concord which will
precede the verb stem:

 <NP monna> <VP <V o a di reka>> - (the) man he MORPH_pres them buys

(The present tense morpheme only occurs if nothing follows the verb)

Moreover, some object concords are merged to the verb stem.

 <NP mosadi <VP <V o bona>> <NP monna> (the) woman she sees (the) man

 <NP mosadi <VP <V o a mpona>> (the) woman she MORPH_pres him-sees.

One example of two objects (there's another nice phenomenon: a VP
syntactically constitutes a complete sentence in Northern Sotho - the
subject NP is only contributing adjunct semantic content and is often
left out):
    
 <VP <V o mphile> mpho> he/she me-gave (a) present.


This is only one example of such an deletion/inversion operation
concerning the object. Another is the reflexive. To solve the problem,
we defined a set of nine "verbal chunks with/without an Object" called
VCO. That is that before any other analysis on the verb is performed
(like, e.g. negation), we put the verbstem together will all required
objects into this chunk. In the following examples, we all call them VCO
for the sake of simplicity, actually the names are different for each of
the structures.

<NP monna> <VP <V o <VCO reka/> <NP dipuku>>> - (the) man he buys books
<NP monna> <VP <V o a <VCO di reka>>> -(the) man he MORPH_pres them buys
<NP mosadi <VP <V o <VCO bona>> <NP monna>>(the)woman she sees (the) man
<NP mosadi <VP <o a mpona>> (the) woman she MORPH_pres him-sees.
<VP <V <VCO o mphile> mpho>> he me-gave (a) present.

We'd like to define these structures not as phrases for they are not
recursive. 

Now the questions:
Is it better to define "chunk" as a subtype of phrase or shall we rather
add it parallel in the hierarchy (We would prefer the subtype) -  how
can we define that chunks are not recursive?

If there is any example matrix grammar available describing such a
phenomenon we'd be happy to be allowed to take a look.

Thanks a lot!
Gertrud