Lexical splits: a novel perspective on the structure of words

Many languages express changes in grammatical meaning through changes in word form, a process known as inflection. Often this is perfectly transparent: adding -s to a verb like 'talk' gives the 3rd person singular present tense (s/he talks), and adding -ed gives the past tense (s/he talked). But sometimes the process is more involved, as with 'go', whose past tense 'went' seems to be a different word entirely. We say here that the word is "split" between two distinct stems. But splits can involve much more than just different forms. Russian verbs, for instance, display a present-past split in the categories of meaning that the forms represent. The present tense marks person, while the past tense marks gender, so that verbs are split in their use of the person and gender features.

By taking a more abstract view of splits we start to notice patterns that are not apparent when looking at the individual phenomena which define splits in isolation. This way of approaching morphological and morphosyntactic irregularity holds open the promise that many diverse instances of irregularity result from combinations of a few basic patterns. We assume a working typology which identifies four binary criteria according to which splits may be distinguished:

1. Structure - does the split involve the forms of the word (e.g. go~went) or the categories of meaning expressed (e.g. person versus gender)?
2. Arrangement - does the split correspond to distinctions that already play a role in the syntax, semantics or phonology of the language, or is it arbitrary?
3. Regularity - does the split affect all words of the same class, or just a few?
4. Relevance - does the split have an effect on anything other than the word itself (e.g. how it interacts with other words)?

Combining these parameters yields sixteen logically-possible split types. Our pilot study shows that each is attested, but the distribution is dramatically skewed, suggesting there are some inherent constraints on possible configurations of splits.

The theoretical implications of adopting our approach are exciting: different models of the architecture of grammar suggest that different types of split should predominate, and that only certain combinations of splits (multiple splits) should be possible; our typological framework allows us to test some of these wide-ranging hypotheses about the organization of inflectional structure in an empirical manner. Further, we would predict that splits which developed out of sound changes result in very different split types to those splits which were induced by changes in syntax or semantics. The thorough typological study we propose is designed to support or to disprove such hypotheses. At a more general level, our investigation of splits offers a novel perspective: accounts of grammatical structure have typically been compartmentalised, so we speak of syntax, of morphology, and of morphosyntax (the intersection of the two). But our approach cross-cuts these distinctions, and provides the means for classifying and analysing shared linguistic structures that operate at a more fundamental level.

In light of the diversity of splits across languages, this research will address the following questions to elucidate what constitutes a possible word:

- What is the typological, genetic and geographic distribution of split types across the world's languages?
- Are there correlations between split types and the way they are manifested?
- Which of the sixteen types of lexical splits can co-occur and what are the restrictions on how they interact with each other? (That is, what types of multiple splits can there be?)
- How do multiple splits arise and how stable are they over time?

1. Who will benefit?

We have identified two key groups outside the academic environment where our research can have an immediate impact. These are (i) members of the public who have an active interest in language and/or socio-cultural diversity in general, and (ii) members of the speech communities of our two case study languages - Skolt Saami (Finno-Ugric, Finland) and Chichimec (Oto-Manguean, Mexico) - in particular those who are studying the language. Based on our research outputs, we will develop resources specifically designed to increase public engagement with the topic of language structure and its complexity.

2. How will they benefit?

(i) members of the public who have an active interest in language

All of us use language on a daily basis and many members of the public are fascinated by it and often eager to learn more about the remarkable complexities we encounter in the languages of the world. But presenting complex linguistic data in a format which is readily understood and appreciated is no easy task and has all too often presented linguists with a real challenge. Advances in visualisation technology, however, allow us to explore new ways of creating more interactive and informative displays. Beside their role in scientific enquiry, such techniques hold the promise of being a more effective tool for the communication of data and analyses to the general public.

For this project, we will use data visualisation to illustrate complex lexical splits, in a clear and insightful manner. The growing popularity of infographics to illustrate facts, figures and data is a good indication of the success of this new technology as a method for engaging with the public and stimulating people to think about language in a new way.

To make our research accessible to a general audience, we will develop an interactive website, allowing users to interact with lexical splits in a number of ways (e.g. by "exploding" splits to see just how they segment the forms of a word; by rotating three-dimensional matrices of word forms to view them from different perspectives; or by rearranging word forms according to values selected by users and seeing the forms dynamically transposed).

Since words are units of language which we all use and understand, this unique way of exploring and interacting with some of the most complex words in the languages of the world will assist us in conveying the notion "possible word" to a wider public.

(ii) members of the Chichimec and Skolt Saami speech communities

We will create two further websites tailored to the Skolt Saami and Chichimec speech communities, with the same interactive functionality as the website for the general public. These language-specific websites will differ from the website for the general public in four key ways: (i) they will be available in Finnish and Spanish, respectively (providing each website in the appropriate lingua franca will maximise reach in the community); (ii) they will contain examples of splits only in the respective language; (iii) they will be accompanied by audio recordings of the different forms involved in the splits; and (iv) they will serve as a pedagogical and/or language revitalisation tool. Further details of these differences are given in the Pathways to Impact statement.

To ensure we reach our intended audience, once these websites are online, we will publicise them through social media (e.g. the Skolt Saami language group on Facebook), the local press and community networks.