We moved from the general categories and concepts of traditional grammar to more specific methods of describing the structure of phrases and sentences. When we concentrate on the structure and ordering of components within a sentence, we are studying the syntax of a language. The word “syntax” comes originally from Greek and literally means “a putting together” or “arrangement.” In earlier approaches to the analysis of syntax, there was an attempt to produce an accurate description of the sequence or ordering “arrangement” of elements in the linear structure of the sentence. In more recent attempts to analyze syntactic structure, there has been a greater focus on the underlying rule system that we use to produce or “generate” sentences.

When we set out to provide an analysis of the syntax of a language, we try to adhere to the “all and only” criterion. This means that our analysis must account for all the grammatically correct phrases and sentences and only those grammatically correct phrases and sentences in whatever language we are analyzing. In other words, if we write rules for the creation of well-formed structures, we have to check that those rules, when applied logically, won’t also lead to ill-formed structures.

For example, we might say informally that, in English, we put a preposition (near) before a noun (London) to form a prepositional phrase (near London). However, if we use this as a rule of the grammar to create structures, we will end up producing phrases like *near tree or *with dog. These don’t seem to be grammatically correct, so we mark them with an asterisk *. We clearly need to be more careful in forming this rule. We might have more success with a rule stating that we put a preposition before a noun phrase (not just a noun).

we saw that a noun phrase can consist of a proper noun (London), a pronoun (you) or a combination of an article (a, the) and a noun (tree, dog), so that the revised rule can produce these well-formed structures: near London, with you, near a tree, with the dog.

When we have an effective rule such as “a prepositional phrase in English consists of a preposition followed by a noun phrase,” we can imagine an extremely large number of English phrases that could be produced using this rule. In fact, the potential number is unlimited. This reflects another goal of syntactic analysis, which is to have a small and finite (i.e. limited) set of rules that will be capable of producing a large and potentially infinite (i.e. unlimited) number of well-formed structures. This small and finite set of rules is sometimes described as a generative grammar because it can be used to “generate” or produce sentence structures and not just describe them.

This type of grammar should also be capable of revealing the basis of two other phenomena: first, how some superficially different sentences are closely related and, second, how some superficially similar sentences are in fact different.