The effect of L1 characteristics on L2 speech has been investigated extensively at the segmental level. This dissertation investigates how L1 prosodic features affect L2 prosodic patterns in the production of the adult L2 speaker (i.e., prosodic transfer). Four speech types were analyzed: 1) L2 English produced by L1 Japanese speakers; 2) L2 Japanese produced by L1 English speakers; 3) L1 English; 4) L1 Japanese. This comparison is interesting, since Japanese and English are typologically very different in terms of their prosodic properties: e.g., English has stress accents, while Japanese has pitch accents; Japanese has a phonemic length contrast, while English does not; English is a stress-timed language, while Japanese is a mora-timed language.

Seven phonetic experiments were conducted to investigate three prosodic phenomena: 1) the contrast between lexically accented and unaccented vowels (Experiments 1-3); 2) the contrast between English tense vs. lax vowels and between Japanese short vs. long vowels (Experiments 4 and 5); 3) the temporal organization across syllables (Experiments 6 and 7). Prosody is phonetically realized by multiple acoustic correlates, which differ from language to language. In the analysis of the collected data, various correlates relevant to each of the three prosodic phenomena were analyzed, taking both phonological and phonetic aspects into account. Additionally, a survey testing phonological awareness of L2 syllable structure was conducted. The results of the survey were analyzed together with the results of the phonetic experiments.

The results supported the following generalizations: first, the transfer patterns of L1 prosodic features in L2 prosody can vary greatly from correlate to correlate. Second, different transfer patterns in the learner’s production can be explained by a difference between L1 and L2 in terms of the phonological status of a relevant prosodic feature. Third, there is a systematic interaction between the prosodic and segmental levels in the transfer of L1 features in L2 speech development. Finally, an L2 speaker’s prosodic system does not necessarily develop in a parallel manner for different dimensions of prosody.