The current study investigates tense switching in narratives written by American learners of Japanese and native Japanese speakers, based on the Discourse Hypothesis (Bardovi-Harlig, 1994). The Discourse Hypothesis predicts that tense-aspect morphology is used to signify grounding; foregrounding information is coded with the past tense more frequently than background information. Although many studies have supported this hypothesis regarding L2 learners in various languages, few studies in Japanese have investigated the use of tense-aspect in this regard. The current study analyzes data based on the same prompts from both learners and native speakers.
10 intermediate learners of Japanese (LJs) and 10 native Japanese speakers (NJs) wrote narratives in Japanese based on five cartoon strips (100 narratives in total). 10 additional native English speakers (NEs) wrote narratives in English based on the same cartoons for comparison. Use of non-past and past tenses for the main verb of each sentence was analyzed. NJs used tense switching for 88% of narratives and showed a strong correlation between the past tense marking -ta with the main story-line, or foregrounding (supporting the Discourse Hypothesis), while LJs used tense switching only 29% with weak evidence to support the hypothesis. However, considering 0% tense switching in English by NEs, the fewer uses of tense switching by LJs may be attributed to L1 transfer. Moreover, the limited number of associations between the tense marking and certain aspectual verbal morphology (e.g., progressive -te iru & non-past) suggests that LJs in this study may have learned them lexically rather than morphologically.
The current data based on the same prompt has shown that intermediate learners? tense switching is far from native-like. This study indicates that the tense marking in Japanese bear stronger aspectual properties, and that without instructions, learners may not acquire tense switching as a discourse organizer beyond the lexical level.