Since the publication of Clahsen and Felser’s (2006) keynote article on grammatical processing in language learners, the online study of sentence comprehension in adult second language (L2) learners has quickly grown into a vibrant and prolific subfield of SLA. As online methods begin to establish a foothold in SLA research, it is important that researchers in our field design sentence-comprehension experiments that adhere to the fundamental principles of research design typical of sentence processing studies published in related subfields of the language sciences. In this article, we discuss and review widely accepted principles of research design for sentence processing studies that are not always followed in L2 sentence processing research. Particular emphasis is placed on the design of experimental items and distractors, the choice and design of the poststimulus distractor task, procedures for presenting stimuli to participants, and methods for trimming and analyzing online data, among others.

This study considers, both transversally and longitudinally, advanced second language (L2) learners’ profile portraits, how these correlate with their sociolinguistic and linguistic performance, and how changes in these portraits over time connect to changes in sociolinguistic performance. The results show a strong correlation between high degrees of learner engagement, as captured in the profile portraits, and the three measures of sociolinguistic and linguistic performance. The longitudinal data point to an increase over time both of levels of engagement and of use of informal sociolinguistic variants. By measuring the impact of learners’ evolving engagement on their use of sociolinguistic variants as they progress to a more advanced level of proficiency in their L2, the present study shows that an index of engagement can usefully summarize the multiple effects captured by the learner profile portraits and can shed light on rates of use of certain forms.

Although morphosyntax has been identified as a major source of difficulty for adult (nonnative) language learners, most previous studies have examined a limited set of largely affix-based phenomena. Little is known about word-based morphosyntax in late bilinguals and of how morphosyntax is represented and processed in a nonnative speaker’s lexicon. To address these questions, we report results from two behavioral experiments investigating stem variants of strong verbs in German (which encode features such as tense, person, and number) in groups of advanced adult learners as well as native speakers of German. Although the late bilinguals were highly proficient in German, the results of a lexical priming experiment revealed clear native-nonnative differences. We argue that lexical representation and processing relies less on morphosyntactic information in a nonnative than in a native language.

Although many theoretical issues revolving around implicit and explicit knowledge in second language (L2) acquisition hinge on the ability to measure these two types of knowledge, few empirical studies have attempted to do so. However, R. Ellis (2005) did develop a battery of tests intended to provide relatively separate measures. This study aims to validate the use of Ellis’s test battery in an English as a foreign language context and to investigate the extent of Chinese first-year university students’ implicit and explicit L2 knowledge. Test scores loaded on two factors, as in R. Ellis (2005), thus demonstrating construct validity for the tests as measures of implicit and explicit knowledge in a population of Chinese university-level learners of English in a Chinese (as opposed to English as a second language) context. These learners were found to have higher scores on measures of explicit knowledge than on those of implicit knowledge because of the instruction they had received and their English learning environment.

Eye-tracking was used to investigate the attentional processes whereby different types of focus on form (FonF) instruction assist learners in overcoming learned attention and blocking effects in their online processing of second language input. English native speakers viewed Latin utterances combining lexical and morphological cues to temporality under control conditions and three types of explicit FonF: verb grammar instruction, verb salience with textual enhancement, and verb pretraining. Chinese native speakers were also tested on control and verb grammar conditions. All groups participated in three phases: exposure, comprehension test, and production test. Verb grammar participants viewed a short lesson on Latin tense morphology prior to exposure. Verb salience participants saw the verb inflections highlighted in bold and red during exposure. Verb pretraining participants took part in an additional introductory phase in which they were presented with solitary verb forms and were trained on their English translations. Instructed participants showed greater sensitivity to morphological cues in comprehension and production. Eye-tracking revealed how FonF affects learners’ attention during online processing and thus modulates long-term blocking of verb morphology.

Research on the age of learning effect on second language learners’ foreign accents utilizes human judgments to determine speech production outcomes. Inferences drawn from analyses of these ratings are then used to inform theories. The present study focuses on rater differences in the age of learning effect research. Three groups of raters who differed in their native language background and language experience participated in the study: inexperienced native English speaker (NES) raters, experienced NES raters, and advanced nonnative English speaker (NNES) raters. All raters evaluated 64 speech samples taken from both NESs and NNESs who varied in their age of arrival in the second-language-speaking country. Results from the study showed that experienced NES raters were better than the other two rater groups at distinguishing NESs from NNESs. Although no rater group differences were found in scaling speakers’ foreign accents or in their interrater reliability, inexperienced NES raters were stricter in their ratings than both experienced NES raters and advanced NNES raters. Implications for research on age of learning effects are discussed.

There is presently a lively debate in second language (L2) acquisition research as to whether (adult) learners can acquire linguistic phenomena located at the interface between syntax and other modules, such as semantics, pragmatics, and lexical semantics, in contrast to phenomena that are purely syntactic in nature. For some researchers, the interface is precisely the place where fossilization occurs and the source of nonconvergence in L2 speakers. In this article we focus on the acquisition of the morphosyntax-semantics interface by examining the acquisition of mood in Spanish relative clauses by native speakers (NSs) of English. In particular, we focus on the contrast illustrated by Busco unas tijeras que corten “I am looking for scissors that cut-subj” versus Busco unas tijeras que cortan “I am looking for scissors that cut-ind.” When the indicative is used, there is a specific pair of scissors that the speaker is looking for. With the subjunctive, any pair of scissors will do, as long as it satisfies the condition expressed by the relative clause; the determiner phrase is nonspecific. In other words, we are dealing not with ungrammaticality, as both moods are possible in these contexts, but rather with differences in interpretation. General results showed that the learners could appropriately select the expected mood. We also saw that performance was not uniform across the various conditions tested. However, variability is not solely a product of L2 acquisition; we show it can be found in NSs as well.

Form-focused instruction studies generally report larger gains for explicit types of instruction over implicit types on measures of controlled production. Studies that used online processing measures—which do not readily allow for the application of explicit knowledge—however, suggest that this advantage occurs primarily when the target structure is similar in the first language (L1) and the second language (L2). This study investigated how explicit knowledge of a structure that does not exist in the L1 affects the initial stage of adult L2 acquisition. Fifty-one Dutch L1 speakers received a short auditory exposure (instruction) to a new language that included differential object marking (DOM), in which animate but not inanimate direct objects are preceded by a preposition. For 26 learners, the instruction was complemented by a brief rule explanation. Afterward, learners’ online processing and explicit knowledge of DOM were measured by means of eye-tracking (visual world paradigm) and oral grammaticality judgments. Results show that metalinguistic information promoted learners’ performance on the grammaticality judgment task. Although differences between the groups were also found on the eye-tracking measure, learners were not able to use DOM to predict the following object.

As part of a research project on the investigation of second language (L2) ultimate attainment in 41 Spanish early and late near-native speakers of L2 Swedish, the present study reports on voice onset time (VOT) analyses of the production of Swedish word-initial voiceless stops, /p t k/. Voice onset time is analyzed in milliseconds as well as in percentages of word duration, thereby accounting for speaking rate effects. The results revealed an overall age effect on VOT production; however, this age effect became salient and statistically significant for all three stops only when speaking rate was taken into consideration. Similarly, when speaking rate was accounted for, only a small minority of the late learners exhibited actual nativelike L2 behavior, and most (but far from all) early learners performed within native-speaker range. The results are taken as an indication for relative VOT, as opposed to absolute VOT, constituting a reliable measure of nativelike L2 stop production, which has important implications for future research on age effects and maturational constraints in L2 acquisition.

This study reports on a sentence processing experiment in second language (L2) French that looks for evidence of trace reactivation at clause edge and in the canonical object position in indirect object cleft sentences with complex embedding and cyclic movement. Reaction time (RT) asymmetries were examined among low (n = 20) and high (n = 20) intermediate L2 learners and native speakers (n = 15) of French in a picture-classification-during-reading task. The results show that a subgroup of learners (13 from the low intermediate and 9 from the high intermediate group) as well as the native speakers produced response patterns consistent with reactivation—with the shortest RTs for antecedent-matching probes presented concurrently with the gap—at clause edge, followed by a second reactivation in the canonical object position. This finding suggests that L2 learners may be able to process real-time input in nativelike ways, despite arguments set forth in previous research of this kind.

Sixty English as a foreign language learners were divided into high-, intermediate-, and low-level groups based on their scores on pretests of target vocabulary and Vocabulary Levels Test scores. The participants read 10 Level 1 and 10 Level 2 graded readers over 37 weeks during two terms. Two sets of 100 target words were chosen from each set of graded readers and were tested on three occasions. The results showed that the relative gains from pretest to immediate posttest were 63.18%, 44.64%, and 28.12% for the high-, intermediate-, and low-level groups, respectively. There was little decay in knowledge on the Term 1 three-month delayed posttest; relative gains ranged from 21.05% for the low-level group to 59.01% for the high-level group. The learning gains in Term 2 were consistent with those from Term 1. The results indicate that prior vocabulary knowledge may have a large impact on the amount of vocabulary learning made through extensive reading.

Grammaticality judgment tests (GJTs) have been used to elicit data reflecting second language (L2) speakers’ knowledge of L2 grammar. However, the exact constructs measured by GJTs, whether primarily implicit or explicit knowledge, are disputed and have been argued to differ depending on test-related variables (i.e., time pressure and item grammaticality).

Using eye-tracking, this study replicates the GJT results in R. Ellis (2005). Twenty native and 40 nonnative English speakers judged sentences with and without time pressure. Analyses revealed that time pressure suppressed regressions (right-to-left eye movements) in nonnative speakers only. Conversely, both groups regressed more on untimed, grammatical items. These findings suggest that timed and untimed GJTs measure different constructs, which could correspond to implicit and explicit knowledge, respectively. In particular, they point to a difference in the levels of automatic and controlled processing involved in responding to the timed and untimed tests. Furthermore, untimed grammatical items may induce GJT-specific task effects.

Although expanding spacing is often regarded as the most effective practice schedule, studies comparing equal and expanding spacing have yielded mixed results. The present study set out to examine whether the amount of spacing and the retention interval may influence the effects of expanding and equal spacing on second language (L2) vocabulary learning. One hundred and twenty-eight Japanese college students studied 20 English-Japanese word pairs. The type of spacing (expanding and equal) and the amount of spacing (massed, short, medium, and long) were manipulated. Results demonstrated a limited, yet statistically significant, advantage of expanding spacing. The finding is significant because this is the first L2 study to find the superiority of expanding over equal spacing. The main effect of the amount of spacing was also significant, producing large effect sizes. Taken together, the results suggest that expanding spacing may facilitate vocabulary learning, although introducing spacing may have a larger effect.

This corpus study brings a second language (L2) research perspective, insights from generative grammar, and new empirical evidence to bear on a long-accepted claim in the World Englishes literature—namely, that inversion with wh-movement in colloquial Indian English is obligatory in embedded clauses and impossible in main clauses. It is argued that this register of Indian English is a L2 variety, functioning as part of a multilingual code repertoire, but that syntactic universals apply to first and second languages alike. Despite recent attempts at formalization, this distribution should be unattested, as such a grammar would fall outside the constraints of Universal Grammar and would contradict proposed discourse-pragmatic principles of natural language. A Perl program was created to search the Indian subcorpus of the International Corpus of English (Greenbaum, 1996) for relevant distributional patterns. Results reveal that wh-inversion in Indian English operates in the same way as in other varieties: It is robustly attested in main clauses and appears only occasionally in embedded clauses where syntactic and pragmatic conditions allow; it is obligatory only with interrogative complementizer deletion. Thus, contrary to the standard account but commensurate with recent corpus studies, users of English in India exhibit knowledge of universal constraints in this domain.

In this article, we aim to contribute to the debate about the use of subordination as a measure of language proficiency. We compare two theories of SLA—specifically, processability theory (PT; Pienemann, 1998) and dynamic systems theory (DST; de Bot, Lowie, & Verspoor, 2007)—and, more particularly, how they address the development of subordinate clauses. Whereas DST uses measures from the complexity, accuracy, and fluency research tradition (see Housen & Kuiken, 2009), PT uses the emergence criterion to describe language development. We focus on the development of subordinate clauses and compare how subordination as such is acquired and how the processing procedures related to a specific subordinate clause word order are acquired in the interlanguage of second language German and Swedish learners. The learners’ language use shows that the use of subordination (as measured by a subordination ratio) fluctuates extensively. From the beginning of data collection, all learners use subordinate clauses, but their use of subordinate clauses does not increase linearly over time, which is expected by DST. When focusing on processability and the emergence of subordinate clause word order, however, a clear linear developmental sequence can be observed, revealing a clear difference between the nonacquisition and the acquisition of the subordinate clause word order rules. Our learner data additionally reveal a different behavior regarding lexical and auxiliary or modal verbs.

Williams’s (2005) study on “learning without awareness” and three subsequent extensions (Faretta-Stutenberg & Morgan-Short, 2011; Hama & Leow, 2010; Rebuschat, Hamrick, Sachs, Riestenberg, & Ziegler, 2013) have reported conflicting results, perhaps in part due to differences in how awareness has been measured. The present extension of Williams (2005) addresses this possibility directly by triangulating data from three awareness measures: concurrent verbal reports (think-aloud protocols), retrospective verbal reports (postexposure interviews), and subjective measures (confidence ratings and source attributions). Participants were exposed to an artificial determiner system under incidental learning conditions. One experimental group thought aloud during training, another thought aloud during training and testing, and a third remained silent, as did a trained control group. All participants were then tested by means of a forced-choice task to establish whether learning took place. In addition, all participants provided confidence ratings and source attributions on test items and were interviewed following the test. Our results indicate that, although all experimental groups displayed learning effects, only the silent group was able to generalize the acquired knowledge to novel instances. Comparisons of concurrent and retrospective verbal report data shed light on the conflicting findings previously reported in the literature and highlight important methodological issues in implicit and explicit learning research.

In this article, we challenge the notion that aptitude—operationalized as grammatical sensitivity as measured by the Words in Sentences section of the Modern Language Aptitude Test—is central to adult second language (L2) acquisition. We present the findings of a study on the acquisition of two properties of Japanese, head-final word order and case marking, by naïve learners of Japanese as a L2 who had no prior knowledge of this language or any other head-final, case-marking language. Participants underwent an input treatment in which they heard and saw basic subject-object-verb sentences in Japanese and were subsequently tested on these basic sentences and also on sentences to which they were not exposed during the treatment (i.e., polar questions and embedded clauses). Reading times on grammatical and ungrammatical sentences served as measures of underlying sensitivity to violations of grammatical word order for both the basic sentences and the novel sentences. Our results yielded three groups of learners: those who showed sensitivity to violations of basic word order, polar questions, and embedded clauses (parameter reset); those who showed sensitivity to violations of basic word order and polar questions only (partial parameter reset); and those who showed sensitivity to violations of basic word order only (no parameter reset). Because our measure of aptitude as grammatical sensitivity did not emerge as a factor distinguishing the three groups from one another, we argue that this component of aptitude is not a factor in whether learners are able to reset parameters. We also found that all participants, regardless of group, demonstrated sensitivity to case-marking violations, suggesting that aptitude as grammatical sensitivity plays no role in the acquisition of underlying features related to case or to the surface-level markings of case in Japanese.

The extent to which individual differences in cognitive abilities affect the relationship among task complexity, attention to form, and second language development has been addressed only minimally in the cognition hypothesis literature. The present study explores how reasoning demands in tasks and working memory (WM) capacity predict learners’ ability to notice English question structures provided in the form of recasts and how this contributes to subsequent development of English question formation. Eighty-one nonnative speakers of English completed three interactive tasks with a native speaker interlocutor, one WM task, and three oral production tests. Prior to the first interactive task, participants were randomly assigned to a task group (simple or complex). During task performance, all learners were provided with recasts targeting errors in question formation. The results showed that learners’ cognitive processes during tasks were in line with the cognitive demands of the tasks, at two complexity levels. The findings suggest that WM was the only significant predictor of the amount of noticing of recasts as well as of learners’ question development. With regard to interaction effects between WM and task complexity, high WM learners who carried out a complex version of the tasks benefitted the most from task-based interaction.

The current project examined whether and to what degree age of acquisition (AOA), defined as the first intensive exposure to a second language (L2) environment, can be predictive of the end state of postpubertal L2 oral proficiency attainment. Data were collected from 88 experienced Japanese learners of English and two groups of 20 baseline speakers (inexperienced Japanese speakers and native English speakers). The global quality of their spontaneous speech production was first judged by 10 native English-speaking raters based on accentedness (linguistic nativelikeness) and comprehensibility (ease of understanding) and was then submitted to segmental, prosodic, temporal, lexical, and grammatical analyses. According to the results, AOA was negatively correlated with the accentedness and comprehensibility components of L2 speech production, owing to relatively strong age effects on segmental and prosodic attainment. Yet significant age effects were not observed in the case of fluency and lexicogrammar attainment. The results suggest that AOA plays a key role in determining the extent to which learners can attain advanced-level L2 oral abilities via improving the phonological domain of language (e.g., correct consonant and vowel pronunciation and adequate and varied prosody) and that the temporal and lexicogrammatical domains of language (e.g., optimal speech rate and proper vocabulary and grammar usage) may be enhanced with increased L2 experience, regardless of age.