SJ connects nouns to the word "and" to create a conjoined noun phrase. The SJ link allows conjoined nouns to appear in almost any situation where a plain, common noun may appear: thus, typically, as subject, object or prepositional object.
+------Spx-----+
+--SJ--+--SJ--+ +---Pg---+
| | | | |
Mike.b and.j-n Joe.b went.v-d fishing.v
+-------Ju-------+
+--Ss-+--MVp--+ +---SJ---+---SJ--+
| | | | | |
he wrote.v-d for.p piano.n-u and.j-n flute.s
In the above examples, the SJ links join the two nouns
to the central coordinator "and". The "and" acts as a head-word,
connecting as if it were a noun itself: in the first case, connecting
with an S link to form the subject of the sentence, and with
a J link in the second example, to become the prepositional
object.
The subtypes SJl, SJr, standing for "left" and "right", are used to maintain sequential ordering; thus, for example:
+-SJl--+--SJr--+
| | |
Jack.b and.j-n Jill.f
Ordering is important for parsing comma-conjoined lists:
+----SJl----+------Spx------+
+SJl+SJr-+ +--SJr--+ +---K---+
| | | | | | |
Jack.b , Jill.f and.j-n Mike.b fell.v-d down.r
The SJ*s subtype is used to coordinate singular nouns, SJ*p coordinates plural, and SJ*u coordinates uncountable (mass) nouns. This is used for enforcing number agreement in various situations:
cars and trucks are vehicles
*cars and trucks is vehicles
*car and truck are vehicles
See also the conjunction overview.
Grammar Documentation Page.