As you’ve learned so far in this book, morphology is concerned with the ways in which words are formed in the languages of the world. Syntax, in contrast, is concerned with identifying the rules that allow us to combine words into phrases and phrases into sentences. Morphology and syntax, then, are generally concerned with different levels of linguistic organization. Morphologists look at processes of lexeme formation and inflection such as affixation, compounding, reduplication, and the like. Syntacticians are concerned, among other things, with phrase structure and movement rules, and rules concerning the interpretation of anaphors and pronouns. Nevertheless, there are many ways in which morphology and syntax interact.

Inflectional morphology is defined as morphology that carries grammatical meaning; as such it is relevant to syntactic processes. Case-marking, for example, serves to identify the syntactic function of an NP in a sentence. Inflectional markers like tense and aspect-affixes identify clauses of certain types, for example, finite or infinitive, conditional or subjunctive. Person and number markers often figure in agreement between adjectives and the nouns they modify, or between verbs and their subjects or objects. In some sense, inflection can be viewed as part of the glue that holds sentences together.

We will first look in more detail at several types of verbal morphology that affect sentence structure by changing what is called the valency of verbs. Valency concerns the number of arguments in a sentence, where arguments are noun phrases like the subject and object selected by the verb of the sentence.

We will look at the borderline between morphology and syntax. While it is usually clear to linguists which phenomena belong to which level of organization, the boundary between the two levels is not always crystal clear. There are cases in which derivational morphemes appear to attach to whole phrases, for example, or elements that seem not quite bound enough to be affixes, but not quite free enough to be viewed as independent words.