Morphological complexity: How is grammar acquired and how do we measure this?

Vaclav Brezina and Gabriele Pallotti

Inflectional morphology has to do with how words change their form to express grammatical meaning. It plays an important role in a number of languages. In these languages, the patterns of word change may for example indicate number and case on nouns, or past, present and future tense on verbs. For example, to express the past participle in German we regularly add the prefix ge- and optionally modify the base. Ich gehe [I go/walk] thus becomes Ich bin gegangen [I have walked].  English also inflects words (e.g. walk – walks – walking – walked; drive – drove – driven) but the range of inflected forms is narrower than in many other languages. The range of morphological forms in a text can be seen as its morphological complexity. Simply put, it is an indicator of the morphological variety of a text, i.e. how many changes to the dictionary forms of the words are manifested in the text.

To find out more about morphological complexity, how it can be measured and how L2 speakers acquire it, you can read:

Gabriele Pallotti and I have been working together to investigate the construct and develop a tool that can analyse the morphological complexity of texts. So far, the tool has been implemented for English, Italian and German verbal morphology. Currently, together with Michael Gauthier from Université Lyon we are implementing the morphological complexity measure for French verbs.

To analyse a text in the Morphological complexity tool, copy/paste the text in the text box, select the appropriate language and press ‘Analyse text now’ (Fig. 1).

Figure 1. Morphological tool: Interface

The tool will output the results of the linguistic analysis that highlights all verbs and nouns in the text and identifies morphological changes (exponences). After clicking on the ‘Calculate MCI’ button the tool also automatically calculates the Morphological Complexity Index (MCI) – see Fig. 2.

Figure 2. Morphological tool output: Selected parts