Draft: March 14, 2008

1.1The Structure of Morphology

The se­cond morphological regularity leveraged by ParaMor to uncover morphological structure is the syntagmatic relationship of lexemes. Natural languages with inflectional morphology invariably possess classes of lexemes that can each be inflected with the same set of paradigmatically opposed morphemes. These lexeme classes are in a syntagmatic relationship. Returning to Spanish, all regular ar verbs use the as and o suffixes to mark 2^nd Person Present Indicative and 1^st Person Present Indicative respectively. Together, a particular set of paradigmatically opposed morphemes and the class of syntagmatically related stems adhering to that paradigmatic morpheme set forms an inflection class of a language, in this case the ar inflection class.

The third morphological regularity exploited by ParaMor follows from the paradigmatic-syn­tag­ma­tic structure of natural language morphology. The repertoire of morphemes and stems in an inflection class constrains phoneme sequences. Specifically, while the phoneme sequence within a morpheme is restricted, a range of possible phonemes is likely at a morpheme boundary. A number of morphemes, each with possibly distinct initial phonemes, could follow a particular morpheme.


Spanish non-finite verbs illustrate paradigmatic opposition of morphemes, the syntagmatic relationship between stems, inflection classes, paradigms, and phoneme sequence constraints. In the schema of Spanish non-finite forms there are three paradigms, depicted as the three columns in each table of Error: Reference source not found. The first paradigm marks the type of a particular surface form. A Spanish verb can appear in exactly one of three non-finite types: as a past participle, as a present participle, or in the infinitive. The three rows of the Type columns in Error: Reference source not found represent the suffixes of these three paradigmatically opposed forms. If a Spanish verb occurs as a past participle, then the verb takes additional suffixes. First, an obligatory suffix marks gender: an a marks feminine, an o masculine. Following the gender suffix, either a plural suffix, s, appears or else there is no suffix at all. The lack of an explicit plural suffix marks singular. The Gender and Number columns of Error: Reference source not found represent these additional two paradigms. In the left-hand table the feature values for the Type, Gender, and Number features are given. The right-hand table presents surface forms of suffixes realizing the corresponding feature values in the left-hand table. Spanish verbs which take the exact suffixes appearing in the right-hand table belong to the syntagmatic ar inflection class of Spanish verbs.

To see the morphological structure of Error: Reference source not found in action, we need a particular Spanish lexeme: a lexeme such as administrar, which translates as to administer or manage. The form administrar fills the Infinitive cell of the Type paradigm in Error: Reference source not found. Other forms of this lexeme fill other cells of Error: Reference source not found. The form filling the Past Participle cell of the tType paradigm, the Feminine cell of the Gender paradigm, and the Plural cell of the Number paradigm is administradas, a word which could refer to a group of women under administration. Each column of Error: Reference source not found truly constitutes a paradigm in that the cells of each column are mutually exclusive—there is no way for administrar (or any other Spanish lexeme) to appear simultaneously in the infinitive and in a past participle form: *admistrardas, *admistradasar.

The phoneme sequence constraints within these Spanish paradigms emerge when considering the full set of surface forms for the lexeme administrar, which include: Past Participles in all four combinations of Gender and Number: administrada, administradas, administrado, and administrados; the Present Participle and Infinitive non-finite forms described in Error: Reference source not found: administrando, administrar; and the many finite forms such as the first person singular indicative present tense form administro. Error: Reference source not found shows these forms (as in Johnson and Martin, 2003) laid out graphically as a finite state automaton (FSA). Each state in this FSA represents a character boundary, while the arcs are labeled with characters from the surface forms of administrar. Morpheme-internal states are open circles in Error: Reference source not found, while states at word-internal morpheme boundaries are solid circles. Most morpheme-internal states have exactly one arc entering and one arc exiting. In contrast, states at morpheme boundaries tend to have multiple arcs entering or leaving, or both—the character (and phoneme) sequence is constrained within morpheme, but more free at morpheme boundaries.

Languages employ a variety of morphological processes to arrive at grammatical word forms—processes including suffix-, prefix-, and infixation, reduplication, and template filling. But this dissertation focuses on identifying suffix morphology, because suffixation is the most prevalent morphological process throughout the world’s languages. The methods for suffix discovery detailed in this thesis can be straightforwardly generalized to prefixes, and extensions can likely capture infixes and other non-concatenative morphological processes.