1.1. Cues to sentence comprehension across languages

Based on the comprehension of sentences involving transitive action verbs, MacWhinney et al. (1984) rank the cues of animacy and word order for thematic interpretation in English: Word Order > Animacy, and in German: Animacy > Word Order. The relative influence of these cues is exemplified in the results of psycholinguistic studies (for review, see Bornkessel-Schlesewsky et al. 2011). The strength of word order as a cue for English is shown where undergoer/object first sentences are less frequent (Hopper & Thompson 1980; Ferreira 1994), can take longer to process (King & Just 1991; Ferreira 2003), and lead to lower comprehension accuracy (King & Just 1991; Ferreira 2003). Animacy also contributes to English sentence comprehension, as speakers tend to place animates in the subject role and prefer agents or experiencers to take the subject rather than object role (Ferreira 1994).

In German, animacy cues speakers to a greater degree, with a preference for the animate participant in the actor role and the inanimate participant in the undergoer role (MacWhinney et al. 1984; Van Nice & Dietrich 2003; Chan et al. 2009). Word order also influences German sentence comprehension, with a preference for actor/subject-first constructions, shown by longer reading times (Fanselow et al. 2002), and decreased judgement accuracy (Bader & Meng 1999) for undergoer/object-first sentences. During sentence comprehension, morphosyntactic cues are quickly integrated and can overcome the word order preference for actor/subject-first constructions (Hopp 2006; Jackson 2008). Further, multiple permissible word orders (e.g. object-initial constructions) make this cue unreliable for interpretation (MacWhinney et al. 1984). Cue prominence may be modulated by the (mis)alignment of thematic, grammatical function, and/or case hierarchies (Schlesewsky & Bornkessel 2003; Bornkessel et al. 2004).

1.2. Thematic Reversal Anomalies to investigate role assignment

Thematic Reversal Anomalies (TRAs) are a linguistic manipulation that effectively probes sentence comprehension and role assignment. TRAs, where the two noun phrases (NPs) of a plausible transitive clause are reversed to elicit a semantic anomaly, allow for direct comparison between thematically plausible and implausible sentences (Kolk et al. 2003; Kuperberg et al. 2003; Hoeks, Stowe & Doedens 2004; Kim & Osterhout 2005; Van Herten et al. 2005). Thus, TRAs provide a strong test case for the ability of cues other than word order to “work against” the dominant order cue in English. We will capitalise on this property of TRAs in the present study. In addition, these manipulations have played a prominent role in the neurolinguistic literature, as the neurophysiological response to thematically plausible (1a) versus implausible (1b) sentences challenged previous assumptions about the neural language processing architecture (see Van de Meerendonk et al. 2009 for a review).

Thematically implausible sentences elicit an animacy violation (marked *), which evokes a neural (event-related potential, ERP) response. Where experiencer-subject (2b) and experiencer-object (3b) violations are directly compared, similar ERPs are observed at the point of animacy violation: for experiencer-subject, at the verb, and for experiencer-object, at the second NP (Paczynski & Kuperberg 2011; Bourguignon et al. 2012). This neural response is qualitatively different compared to that elicited by violations of agent-subject verb constructions (1b) (Kolk et al. 2003; Kuperberg et al. 2003; Hoeks et al. 2004; Kim & Osterhout 2005; Van Herten et al. 2005; Bourguignon et al. 2012; Kyriaki et al. 2020). The observed ERP differences to violations of differing verb classes support the conception that agent and experiencer verbs are comprehended differentially at the neural level. Behavioural results also show higher grammaticality judgement and comprehension accuracy for agent-subject over experiencer-subject sentences (Bourguignon et al. 2012; Kyriaki et al. 2020). However, response accuracy results cannot provide insight into role assignment.

Cross-linguistic comparisons of TRA violations also align with the CM’s proposed differences in relative cue weightings across languages (see Bornkessel-Schlesewsky et al. 2011 for overview). The neural response elicited by agent-subject verb (ASV) violations qualitatively differs between English and German (Bornkessel-Schlesewsky et al. 2011). In English, the prominent cue of word order leads to the implausible interpretation of an inanimate acting upon an animate (Kuperberg et al. 2003; Kim & Osterhout 2005). In German, TRA violations are resolvable in some cases, where flexible word order allows the possibility of reinterpretation (Bornkessel et al. 2002; Bornkessel-Schlesewsky et al. 2011). Here, where case marking is ambiguous, the cue strength of animacy in German can lead an ASV TRA to be resolved with reanalysis to an object-first interpretation (Bornkessel-Schlesewsky et al. 2011).

Prior research in English further shows a verb class difference in behavioural and neural responses to TRAs (Bourguignon et al. 2012; Kyriaki et al. 2020). While cross-linguistic comparisons for ASV TRAs have been examined across English and German (Bornkessel-Schlesewsky et al. 2011), other verb classes have not been compared. Non-default experiencer-object verbs have been shown to reduce the applicability of word order for comprehension in German (Schlesewsky & Bornkessel 2003; Bornkessel et al. 2004) but the effect of experiencer-subject verbs has not been directly investigated. The use of a less prototypical subject/Actor (experiencer) may lead to a stronger prominence of animacy (and weaker prominence of word order) as a cue, particularly in the comprehension of sentences with an inanimate NP1 and animate NP2. This hypothesis is based, in part, on the observation that experiencer-subjects tend to differ in their morphosyntactic properties from agent-subjects in prototypical transitive sentences (cf. Hopper & Thompson, 1980, for this notion), for example in terms of case marking patterns (see Bickel et al. 2014, for a review and empirical analysis). We thus suggest that, just as they tend to be associated with non-default morphosyntactic patterns, less prototypical subject/Actor arguments may lead to non-default comprehension strategies. Comparing the way in which English and German speakers assign roles in agent-subject and experiencer-subject verb sentences would thus contribute towards the current understanding of sentence interpretation built upon neurolinguistic research. This also allows for a direct comparison of verb class across two languages which differentially rely on CM cues for interpretation (MacWhinney et al. 1984).

1.3. The present study

The present study is an internet-based sentence reading survey, aiming to investigate cross-linguistic differences in English and German thematic role assignment across agent- and experiencer-subject TRAs. While case marking is a cue to sentence comprehension it German, it is not always informative, such as in sentences where both NPs are feminine or plural (MacWhinney et al. 1984; Kempe & MacWhinney, 1999). German TRAs were designed with ambiguous case marking, allowing them to be resolvable with reconceptualization to an object-first word order. By constructing sentences with ambiguous case marking in this way, case marking can be rendered uninformative to interpretation while the sentence remains naturalistic. This also allows a more direct comparison of German to English (which does not use case marking). Example stimuli are shown in Table 1. We developed a comprehension task which prompts participants to identify either the actor or undergoer. This task was modelled after the task used in MacWhinney et al. (1984) who prompted participants for the actor/subject, the task described in Kyriaki et al. (2020) who prompted for either the actor or undergoer.

We predict (H1) that English speakers will display a predominantly word-order-based comprehension strategy, most often selecting the NP1 as the actor and NP2 as the undergoer regardless of animacy cues. We hypothesise (H2) that German speakers will display a predominantly animacy-based comprehension strategy, most often selecting the animate NP as the actor and inanimate NP as the undergoer regardless of word order cues. Lastly, we predict (H3) that object-initial interpretations in German will occur more frequently in sentences containing experiencers compared to sentences containing agents. We employed a 2 × 2 × 2 × 2 design with factors Verb Class (Agent-Subject Verb or Experiencer-Subject Verb), Animacy (of the NP1 and NP2; Animate-Inanimate or Inanimate-Animate), Question Type (Actor or Undergoer probe) and Language (English or German).

2.1. Participants

At the time of the study, all participants were currently residing in Australia, but German speakers had resided within a German-speaking country within the past two years (i.e., within the last two years, had moved from a German-speaking country to reside in Australia). To be eligible, participants were required to report no language disorder or intellectual impairment and had not learned any languages other than their native language (English or German) prior to the age of 5 years. Thirty-eight native English speakers (23 female, mean age 25.71 ± 0.87) took part in the English survey. Fourteen reported that they spoke a second language. Participants were asked to report their highest level of education. Two participants (5.26%) had not completed secondary school, 19 (50%) had completed secondary school, and 17 (44.74%) had completed a Bachelor’s degree or higher. Twenty-six native German speakers (8 female, mean age 27.73 ± 1.02) took part in the German survey. All spoke English in addition to German, with four also speaking a third language. Thirteen (50%) had completed secondary school, and thirteen (50%) had completed a Bachelor’s degree or higher.

2.2. Materials

2.3. Procedure

Participants undertook the survey via an online survey provider (Qualtrics) in English or German. The first page presented the information sheet and consent form, and participants provided consent by selecting “I agree”. After providing demographic information to confirm eligibility, instructions were presented. Two example sentences and practise questions (one Actor, one Undergoer probe) were presented. For the experimental part of the survey, sentences and questions were presented individually page-by-page, with no option to return to a previous page. Participants were instructed to read each sentence once, before pressing the “next” button to proceed. The following page displayed a question about the previous sentence with two possible answers. Participants were instructed to select the answer they believed was most correct, then press “next”. The survey lasted for approximately 20 minutes. At the survey’s conclusion, participants were offered the opportunity to provide their details to receive an honorarium.

4.1. English response choice

The Noun Animacy × Verb Class × Question Type × Language interaction is visualised in Figures 1 and 2 for actor and undergoer probes, respectively. For English speakers, post-hoc contrasts indicate that A-I sentences elicited significantly higher word-order-based comprehension compared to I-A sentences regardless of question type and verb class (for the actor probe, ASV p < 0.001, ESV p = 0.003; for the undergoer probe, ASV p < 0.001, ESV p < 0.001).

4.2. German response choice

For German, the pattern of results differed more widely across verb class and question type. For actor probes, ASV sentences showed no significant difference (p = 0.08) in response between A-I and I-A sentences, indicating a similar response pattern regardless of noun animacy. For ESV, A-I constructions led to a significantly higher proportion of word-order-based interpretations, while I-A led to more animacy-based interpretations (p < 0.001). When probed for the undergoer, ASV A-I constructions elicited significantly more word-order-based responses than did I-A constructions (p = 0.007), but there was no difference between noun animacy conditions for ESV sentences (p = 0.53). Here, both A-I and I-A ESV constructions elicited a response strategy where the NP1 was more often selected as the undergoer (regardless of animacy).

5.1. Competition Model cue prominence

In line with Competition Model predictions (CM; Bates et al. 1982; MacWhinney et al. 1984), English and German speakers relied on both word order and animacy as cues to interpretation, but to different degrees. The dominant cue to English role assignment was word order for both ASV and ESV sentences. English speakers showed a strong tendency to select the NP1 as the actor, matching the results of Bates et al. (1982), who found that in noun-verb-noun constructions, English speakers select the NP1 as the actor most often. We also observed a slight animacy preference corresponding with Dowty’s (1991) thematic proto-roles. English speakers preferred animate NPs as the actor/proto-agent (and inanimate NPs as the undergoer/proto-patient). When probed for the actor, animate NP1s were selected more often than inanimate NP1s. This illustrates that subordinate cues influence thematic interpretation concurrently to dominant cues even under circumstances where the dominant cue is thought to shape interpretation in a quasi-deterministic manner.

For German speakers, the ambiguous case marking of NPs (due to feminine gender or plural number) rendered case uninformative to role assignment. Both animacy and word order cued sentence interpretation, with animacy a prominent cue, but not completely dominant over word order as hypothesised. Nevertheless, animacy strongly determined interpretation: compared to English, inanimate NPs were selected as actors less often, and animate NPs were selected as undergoers less often. In addition, sentential and experimental context – here, question type and verb class – strongly influenced the relative prominence of both word order and animacy as cues to interpretation, which will be discussed below.

Overall, our findings support the CM’s claim that there is no principled difference between cue weightings that represent tendencies and those that represent deterministic rules (MacWhinney et al. 1984, p. 129). However, they also go somewhat beyond the original formulation of the CM, in suggesting that cue weightings might be upgraded or downgraded in the context of other cues. As we discuss further below, the weighting of an animacy-based strategy over a word-order-based strategy was increased for sentences with non-default (experiencer-subject) verbs and with undergoer-focused questions, particularly where word order was more flexible (i.e. in German as opposed to English). This suggests a possible contextualisation of cue utilisation in a manner not directly envisaged by the CM. We will return to this point in the discussion of theoretical implications in section 5.4.

5.2. Question context retrospectively influences topicality

The focus of the comprehension question significantly affected response choice, and this was particularly apparent in German, where question type interacted with verb class and animacy. The nature of the comprehension question retrospectively influenced semantic interpretation, likely by promoting the NP1 to sentence topic (what the sentence “is about”; Reinhart 1981). In German, the topical entity is preferred in the sentence initial position (Rosengren 1993; Büring 1999; Frey 2005; Schumacher & Hung 2012). Accordingly, when probed for the undergoer of an I-A construction, animacy-driven object-initial interpretations were more common, with the inanimate NP1 reconceptualised as the undergoer and topic. Strikingly, a significant difference between verb classes was observed when noun animacy and question type did not align. Responses to ASV versus ESV significantly differed where the question probed for the actor of an I-A construction and where the question probed for the undergoer of an A-I construction, with animacy a stronger cue in both animacy conditions for ESV. These verb class effects will be discussed in the following section.

In contrast to German, we did not see a similar topicality effect in English, which we posit to be due to the cue prominence (and inflexibility) of word order in English. Our findings are supported by language-specific differences in language production as a function of word order flexibility (for review, see Myachykov et al. 2011). Here, when the experimental context draws attentional focus to the undergoer of a transitive event, English speakers are more likely to produce a passive sentence to describe the event. Languages with a flexible word order (e.g. Russian), by contrast, show a higher number of object-first sentences and almost no passives in similar manipulations (Myachykov et al. 2011). Our results show that similarly to language production, language comprehension is influenced by the attentional affordance of the experimental context (here, question focus) differentially across languages. These results are also in line with previous assertions that experimental context can influence responses to linguistic violations (Osterhout & McKinnon 1996; Osterhout et al. 2002; Sassenhagen et al. 2014; Kyriaki et al. 2020).

5.3. Non-default verbs promote subordinate cues

Verb class effects on role assignment were highly influenced by the interaction of noun animacy and question focus for German. The general pattern of results was similar for ASV sentences across noun animacy conditions and question types. However, in German ESV sentences, the non-default verb class was associated with more frequent reinterpretation to object-first constructions, particularly when the question probed for the undergoer. English speakers showed no significant differences in response across verb classes, although the percentage of word-order-based responses was higher for ASV over ESV sentences. This held across noun animacy (A-I and I-A) and question conditions (Actor and Undergoer probes). The reduced cue strength of word order for ESV sentences suggests that the non-default verb class increased the prominence of the subordinate cue of animacy. These findings are supported by behavioural results of a recent neurophysiological study of English speakers (Kyriaki et al. 2020), which found that response accuracy was lower for ESV compared to ASV, indicating that participants processed the two verb classes differently.

Overall, we assume that the modulation of interpretations by verb class was likely driven by the divergence of experiencers from agents (for review, see Rozwadowska 2017). While agent- and experiencer-subjects are both required to be animate, the latter is a less prototypical actor/proto-agent (Dowty 1991; Van Valin et al. 1997; Primus 1999) and this appears to promote subordinate cues for interpretation.

5.4. Theoretical implications

Our results show that, within the broader interpretation patterns shaped by dominant cues (e.g. word order in English), subordinate cues (e.g. animacy in English) also have a measurable effect on sentence interpretation. This is in line with the assumption of grammatical frameworks that allow for probabilistic constraint rankings (e.g. stochastic Optimality Theory; Boersma & Hayes 2001) or hard and soft constraints (e.g. Bresnan et al. 2001; Sorace & Keller 2005). Intriguingly, the relative weighting of subordinate cues was enhanced in the presence of a non-default verb class (experiencer-subject verbs) even though the thematic role hierarchy between subject and object was the same as in default (action) verbs. This indicates that – in addition to their well-known morphosyntactic differences from default verb classes (e.g. Primus, 1999) – non-default verb classes also engender non-default comprehension strategies, and this applies regardless of the “degree of deviance” from the default. While promotion of non-default strategies was stronger in German in the present study, likely due to the availability of flexible word order, it was also observable in English.

Similar considerations appear to hold for “non-default questions”, i.e. those targeting the Undergoer rather than the Actor role. Strikingly, although the type of question encountered was not clear until after sentence presentation, Undergoer questions appeared to boost the prominence of the Undergoer (likely by enhancing topicality, as discussed above) and again promote the use of non-dominant interpretation strategies. This effect parallels that of non-default verb class in that it was stronger where flexible word orders were available (German) as opposed to when they were not (English). Moreover, verb class and question type coalesced in German, leading to the highest proportion of interpretations differing from the default.

Taken together, these observations suggest that cue weightings are surprisingly flexible and can be shifted by a number of contextual and environmental influences. These can be language internal, such as the use of non-default verb classes, or task-related, such as the use of different question types. In all cases, deviations from default configurations seem to promote the use of non-default interpretation strategies. Further, the present results suggest a complex interaction of cues indicative of a weighting of constraints that goes beyond a strictly hierarchical (ordinal) ranking and is more in line with probabilistic models of grammar and language processing (cf. Jurafsky, 2003).