Measuring implicit knowledge of stem-vowel alternations in German strong verbs: A visual-world eye-tracking study


In native language comprehension, people constantly integrate lexical, morphosyntactic, pragmatic and contextual information to predict upcoming input (Altmann & Kamide, 1999; Huettig et al., 2011), which facilitates efficient communication (Jaeger & Snider, 2013). Adult L2 learners, however, manifest difficulties in exploiting grammatical cues to generate such anticipations (Kaan, 2014). Some studies found L2 sentence processing to rely more on lexical-semantic rather than on grammatical information (e.g., Hopp, 2015).

Our study investigates whether advanced L2 German learners (L1 Dutch) can use the grammatical information encoded in stem-allomorphs of German strong verbs in comprehension. Morphosyntactic information in German strong verbs is not only encoded through affixation but also through stem-allomorphy. As a consequence, the difference between the 3rd p. sg. and the 2nd p. pl. in present tense is marked only through a stem-vowel change. We wish to examine whether L2 learners can use the changed vowels in auditory input as a cue for syntactic number.

We compare data of 20 learners of German to those of 20 native speakers in a visual-world eye-tracking experiment using a sentence-picture matching task. Participants are exposed to two pictures, varying in the number of referents depicted, in combination with auditory sentences in which the vowel of the verb stem represents the first reliable cue for number. Successful exploitation of the morphosyntactic information encoded in the stem-allomorphs is measured as anticipatory eye-movements towards the correct picture.

The findings may have important theoretical and methodological implications. The absence of anticipation in the L2 group would confirm the processing differences between L2 and L1 speakers in sentence comprehension. However, the presence of anticipatory eye-movements would imply that our method could be used as a measure of implicit morphosyntactic knowledge, and be compared to measures of explicit knowledge. Furthermore, the method can be implemented in combination with learning treatments.




Altmann, G. T. M., & Kamide, Y. (1999). Incremental interpretation at verbs: Restricting the domain of subsequent reference. Cognition, 73, 247-264.

Hopp, H. (2015). Semantics and morphosyntax in predictive L2 sentence processing. International Review of Applied Linguistics, 53, 277-306.

Huettig, F., Rommers, R., & Meyer, A. S. (2011). Using the visual world paradigm to study language processing: A review and critical evaluation. Acta Psychologica, 137(2), 151-171.

Jaeger, T. F., & Snider, N. E. (2013). Alignment as a consequence of expectation adaptation: Syntactic priming is affected by the prime’s prediction error given both prior and recent experience. Cognition, 127(1), 57-83.

Kaan, E. (2014). Predictive sentence processing in L2 and L1: What is different? Linguistic Approaches to Bilingualism, 4(2), 257-282.