This is an introduction to the structure of sentences in human languages. It assumes no prior knowledge of linguistic theory and little of elementary grammar. It will suit students coming to syntactic theory for the first time either as graduates or undergraduates. It will also be useful for those in fields such as computational science, artificial intelligence, or cognitive psychology who need a sound knowledge of current syntactic theory.

For the past two decades, it has widely been assumed by linguists that there is a single computational operation, Merge, which is unique to language, distinguishing it from other cognitive domains. The intention of this paper is to progress the discussion of language evolution in two ways: (i) survey what the ethological record reveals about the uniqueness of the human computational system, and (ii) explore how syntactic theories account for what ethology may determine to be human-specific. It is shown that (...) the operation Label, not Merge, constitutes the evolutionary novelty which distinguishes human language from non-human computational systems; a proposal lending weight to a Weak Continuity Hypothesis and leading to the formation of what is termed Computational Ethology. Some directions for future ethological research are suggested. (shrink)