Our study addresses the following research questions: To what extent is L2 comprehenders’ online sensitivity to morphosyntactic disambiguation cues affected by L1 background? Does noticing the error signal trigger successful reanalysis in both L1 and L2 comprehension? Can previous findings suggesting that case is a better reanalysis cue than agreement be replicated and extended to L2 processing when using closely matched materials?

We carried out a self-paced reading study using temporarily ambiguous object-initial sentences in German. These were disambiguated either by number marking on the verb or by nominative case marking on the subject. End-of-trial comprehension questions probed whether or not our participants ultimately succeeded in computing the correct interpretation.

We tested a total of 121 participants (25 Italian, 32 Russian, 32 Korean and 32 native German speakers), measuring their word-by-word reading times and comprehension accuracy. The data were analysed using linear mixed-effects and logistic regression modelling.

All three learner groups showed online sensitivity to both case and agreement disambiguation cues. Noticing case disambiguations did not necessarily lead to a correct interpretation, whereas noticing agreement disambiguations did. We conclude that intermediate to advanced learners are sensitive to morphosyntactic interpretation cues during online processing regardless of whether or not corresponding grammatical distinctions exist in their L1. Our results also suggest that case is not generally a better reanalysis cue than agreement.

Our three L2 participant groups’ native languages were carefully chosen so as to create systematic typological contrasts. Our experimental materials and conditions were more closely matched compared to previous studies on German object-initial sentences, and our experimental design allowed us to link participants’ reading profiles to successful comprehension.

L1 influence on L2 processing is more limited than might be expected. Contra previous findings, even intermediate learners show sensitivity to both agreement and case information during processing.