Syntax
X-Bar Theory and Constituent Structure
General claim of X-Bar theory:
The words in sentences (and phrases) have not just a linear order but also a hierarchical structure.
I. Hierarchical structures
In generative syntax, hierarchical structures are organised in such a way that two syntactic objects are joined to form a larger syntactic object (unit, constituent).
Hierarchical structures are represented in tree diagrams and syntactic objects or units are then referred to as nodes (cf. A, B, C below).

Larger syntactic units (such as C above) can join with another syntactic object or another complex syntactic unit to form a new unit. Note that not more than two syntactic objects can be joined to form a new object, resulting in binary branching structures.

II. Structural relations
The hierarchies in tree diagrams can be expressed with reference to structural relations. The basic structural relations are defined below:
(a) Motherhood:
A node A is the mother of node B, if it directly contains it. B is then referred to as A's daughter.
Example: In the tree diagram above C is the mother of A and B, and G is the mother of E and F.
(b) Sisters/Sisterhood:
A node A is node B's sister if it has the same mother as B.
Example: In the tree diagram above A and B are sisters.
(c) Dominance:
A node A dominates node B if it is higher up in the tree than A and contains it.
Example: In the tree diagram above G dominates all other nodes since it contains them.
Principles of X-Bar Theory
The X-Bar Model: Lexical Categories
X-Bar Theory and Constituent Tests
Exercises on Constituent Structure
- Basic terminology 1
- Basic terminology 2
- Basic terminology 3
- The structure of VPs
- Ambiguous VPs
- The structure of NPs
- Ambiguous NPs
- The structure of APs
- The structure of PPs
- Movement test: Exercise
- Proformt test: Exercise
- Coordination test: Exercise
- Intrusion test: Exercise
- Sentence fragment test: Exercise
- Omission test: Exercise
- VP-deletion: Exercise
- Syntactic tests 1
- Syntactic tests 2
- Explain ungrammaticality