Chapter4 Syntax What is syntax?n n It studies how words are combined to form sentences and the interrelationships between elements in sentence structures. Syntactic relations Positional relation refers to the sequential arrangement ofwords in a language. Relation of substituability refers to classes or sets ofwords substitutable for each other grammatically in thesame sentence structures. Relation of co-occurrence: a word of one set may permitthe occurence of a word of another set to form a sent