Singular-plural asymmetry in L2 English number processing: A sentence-picture matching study of Japanese learners of English

2026/01/222026/02/26 / Yu Tamura

Aims and Objectives

This study investigates whether Japanese learners of English automatically map English number morphology onto conceptual number in both directions. Two research questions guide the study:
1) Mismatch costs: Do L2 learners show reaction-time slowdowns when:
a) A singular noun is paired with a plural picture?
b) A plural noun is paired with a singular picture?
L1 speakers serve as a baseline to establish expected mismatch effects.
2) Directional asymmetry: If mismatch costs occur, are they equivalent in both directions, or is there a systematic asymmetry?

Methodology

The study employed a sentence-picture matching task that crossed noun number (singular vs. plural) with picture number (match vs. mismatch), extending previous unidirectional designs to test both directions of number mapping in L2 processing. Reaction times (RTs) served as the primary dependent measure.

Data and Analysis

Thirty-two L1 English speakers and ninety-six Japanese L2 learners (CEFR B1–B2) each completed 200 trials (80 target items and 120 fillers). Incorrect trials were excluded, and extreme RTs were trimmed before the analysis. RTs were analyzed using inverse-Gaussian generalized linear mixed-effects models, with sentence length and trial order included as covariates.

Findings

L1 speakers showed significant RT slowdowns for both mismatch types, confirming automatic singular-plural mapping. In contrast, L2 learners exhibited a slowdown only when a singular noun was paired with a plural picture, and no effect when a plural noun was paired with a singular picture, revealing a processing asymmetry. For Japanese learners, plural nouns did not consistently activate conceptual plurality.

Originality

This is the first study to examine both directions of morphological-conceptual number mismatch in L2 processing, extending Jiang et al. (2017), which tested only the singular-noun/plural-picture mapping.

Significance

These findings refine the Morphological Congruency Hypothesis by showing that incongruent L2 morphemes can lead to direction-specific processing weaknesses in learners’ conceptual mapping.

Tamura, Y. (2026). Singular-plural asymmetry in L2 English number processing: A sentence-picture matching study of Japanese learners of English. International Journal of Bilingualism. https://doi.org/10.1177/13670069261422017 [Open Access]

Investigation of the relationship between animacy and L2 learners’ acquisition of the English plural morpheme

2022/10/142023/05/20 / Yu Tamura

It has been argued that languages differ in the extent to which they allow plural forms of nouns according to the Animacy Hierarchy. Japanese distinguishes between animate and inanimate nouns; the latter are less likely to receive plural markers (e.g., ? hon‐tachi), unlike English. This L1‐L2 difference might cause difficulty in acquiring the plural morpheme. The present study thus investigates the influence of animacy on the processing of the English plural morpheme in online sentence processing. In this study, 34 Japanese university students engaged in a moving window version of a self-paced reading task, during which they also judged whether the number of words presented was one or two when prompted. If animacy matters, Japanese EFL learners might not show an interference effect of this second task for inanimate nouns. However, as no such effect was found, the prediction based on the animacy hierarchy was not confirmed.

Tamura, Y. (2023). Investigation of the relationship between animacy and L2 learners’ acquisition of the English plural morpheme. Journal of Psycholinguistic Research, 52, 675–690. https://doi.org/10.1007/s10936-022-09915-2 [Read Online]

Rule-based or efficiency-driven processing of expletive there in English as a foreign language

2022/04/012023/11/10 / Yu Tamura

Although Native speakers (NSs) of English make plural agreement in preverbal-subject sentences (e.g., A pen and eraser *is/are…), previous studies have demonstrated that they prefer singular – not plural – agreement between verbs and conjoined noun phrases (NPs) in expletive there constructions (e.g., there is/are a pen and an eraser…), showing efficiency-driven processing prioritization of agreement between nearest constituents. This paper assesses whether Japanese L2 learners of English (JLE) show this tendency. The results of two self-paced reading experiments together indicated that even though efficiency-driven processing was available to L2 learners, their use was unstable due to the repeated exposure to there are NP_pl– and NP_pl-type sentences during the task. It seems possible that repeated exposure triggered learners’ knowledge that that conjoined NPs are always plural. Hence, it could conceivably be hypothesized that a learner’s specific knowledge intervenes the efficiency-driven processing strategy.

Tamura, Y., Fukuta, J., Nishimura, Y., & Kato, D. (2023). Rule-based or efficiency-driven processing of expletive there in English as a foreign language, 61, 1577–1606. International Review of Applied Linguistics in Language Teaching. https://doi.org/10.1515/iral-2021-0156 [Author Manuscript]

L2 learners’ number agreement in the expletive there constructions: Conjoined NP always plural?

2021/03/092021/04/13 / Yu Tamura

The purpose of this study was to investigate whether L2 learners of English can employ efficiency-driven number agreement processing with conjoined noun phrases (NPs) in expletive there constructions (ETC). Previous studies reported that native speakers of English prefer singular agreement over plural agreement when conjoined NPs are used in ETCs (e.g., there is a pen and an eraser…), which implies that native speakers (NSs) of English prioritize efficiency over the canonical agreement. The present study examined whether L2 learners can show similar processing tendencies. In Experiment 1, an offline error correction task was administered to Japanese L2 learners of English to see the learners’ explicit knowledge. The results indicated that they tend to make a plural agreement in ETCs. In Experiment 2, L2 learners were compared with NSs in the self-paced reading task, which demonstrated that—unlike the NS group—L2 learner group analyzed conjoined NPs as a plural. The fact that L2 learners preferred plural agreement could be due to their explicit knowledge that conjoined NP should always be plural. This knowledge led to a non-nativelike agreement in ETC in online sentence processing.

Tamura, Y., Fukuta, J., Nishimura, Y., & Kato, D. (2021). L2 learners’ number agreement in the expletive there constructions: Conjoined NP always plural? Reports of 2020 Studies in The Japan Association for Language Education and Technology, Chubu Chapter, Fundamentals of Foreign Language Educational Research Special Interest Group (SIG), 2–23. [PDF] (Password to open the PDF: kisoken202001)

Japanese EFL Learners’ Sentence Processing of Conceptual Plurality: An Analysis focusing on reciprocal verbs

2018/07/302020/09/16 / Yu Tamura / 1件のコメント

This study aimed to investigate how Japanese EFL learners, whose first language does not have obligatory morphological number marking, process conceptual plurality. The targeted structure was reciprocal verbs, which require conceptual plurality to interpret their meanings correctly. The results of a sentence completion task (SCT) confirmed that participants could use reciprocal verbs reciprocally in English. In a self-paced reading experiment, participants read sentences with reciprocal verbs and those with optionally transitive verbs (e.g., while the king and the queen kissed/left the baby read the book in the bed). There was no reading time delay for reciprocal verbs but a delay for optionally transitive verbs. Therefore, the participants succeeded in processing L2 conceptual plurality in the online sentence comprehension task.

Tamura, Y., Fukuta, J., Nishimura, Y., Harada, Y., Hara, K., & Kato, D. (2019). Japanese EFL learners’ sentence processing of conceptual plurality: An analysis focusing on reciprocal verbs. Applied Psycholinguistics, 40, 59–91. doi:10.1017/S0142716418000450 [Author Manuscript]

The notional number attraction in English as a foreign language: A self-paced reading study

2015/10/192021/03/18 / Yu Tamura

The purpose of the present study is to investigate whether or not the notional number attraction phenomenon is evident during L2 learners’ online processing of subject–verb agreement. L2 sentence processing studies have frequently reported the L2 learners’ online insensitivity to number mismatches, and it has been claimed that L2 learners have difficulty in representing grammatical number features, or they have a tendency to fail to access the number features in online tasks. L2 learners’ sensitivity to “notional number”, however, has not been considered by researchers. Hence, this research conducted a self-paced reading study targeting highly proficient Japanese learners of English (N = 28). The participants read the three types of sentences; (a) control (e.g., everyone in the room was/were…), (b) notional attraction (e.g., everyone in the team was/were…), and (c) grammatical attraction (e.g., everyone in the halls was/were…). In order to examine the participants’ sensitivity to number attractions, the differences in the reading times between the number matched and the mismatched verbs (was/were) were compared among the attraction types. The observed reading time differences in the grammatical and notional attraction condition were different than in the control condition, indicating that both attraction phenomena were evident. L2 learners’ imperfect representation of number features, which we call representation vulnerability, was discussed.