Coordination of clauses

In addition to a classification in sentence types [Syntax – Chapter 1] (declaratives, imperatives, interrogatives, and exclamatives), sentences can be classified according to their internal complexity. A sentence is simple when it consists of a single independent clause (‘Mohammed arrived on time’) while it is complex when it consists of a main and a subordinate clause or of two (or more) coordinate clauses. In principle, the level of subordination is unlimited (‘John said that I think that Mohammed claimed that Kazuko is convinced that you arrived on time’) although in practice there are limitations of the sentence length due to cognitive limitations (for example, working memory). The main difference between subordination and coordination is that coordinated clauses have the same status while the main clause and the subordinated one do not. For example, the two clauses that form the coordinated sentence ‘Mohammed arrived on time and Sarah arrived late’ might be used as independent sentences. In contrast, subordination is a syntactic mechanism by which a clause becomes dependent on another one. Therefore, in the complex sentence ‘If Mohammed arrives on time, Miriam will be surprised’, the subordinate clause ‘if Mohammed arrives on time’ could never be used as an independent sentence while the main clause ‘Miriam will be surprised’ might. By coordination we mean the combination of at least two constituents / [Syntax – Section 2.0.1], often belonging to the same syntactic category such as phrases [Syntax – Chapter 4], verb phrases, or clauses, either through conjunction or constituents noun juxtaposition. Conjunction refers to combining at least two constituents through the use of conjunctions / conjunctions [Lexicon – Section 3.9] such as and, but, and or. Juxtaposition, on the other hand, refers to the coordination of constituents without such conjunctions. This section focuses on properties of coordinated clauses. The reader is referred to sections on other types of phrases for a discussion of coordination of those constituents.