Grammatical Relations
1. Structural constituents and their functions in sentences
tree diagrams of sentences show two important characteristics of constituents
 constituents have an internal structure
 constituents perform specific grammatical functions in a sentence
Compare:
(in the trees below, triangles are used to simplify the representation of the internal
structure of the NPs)
S
NP
VP
V
The boy
frightened
NP
the people in the room.
S
NP
VP
V
The people in the room frightened
NP
the boy
the two sentences have the exactly same structural constituents,
but those structural constituents have different grammatical relations in
the two sentences
Thus:
 tree diagrams reveal the structural properties of constituents
 the linear order of elements
 the labeling of elements parts of speech
 the grouping of elements into structural constituents
 tree diagrams show the grammatical relations of constituents in a
sentence
 Subject
 Object
 tree diagrams can give a structural definition of the grammatical relations
Subject and Object
in English:
 the Subject of a sentence is the NP immediately dominated by S and
precedes VP
 the Object of the sentence is the NP immediately dominated by VP
 the Object of a preposition is the NP immediately dominated by PreP
 the distinction between structural properties and grammatical relations is
crucial in determining the meaning of a sentence