We present an ongoing study which investigates the interplay between external sandhi – specifically word-final /r/ – and word-initial glottalisation in English-accented German compared to native English in relationship to accent and phrasing. In Southern British English word-final /r/ is usually not articulated, but it can surface if the following word starts with a vowel [2]. In German, word-initial vowels are glottalised in the majority of cases [3], while in English word-initial glottalisation is less frequent and motivated by phrase boundaries and prominence [4]. Glottalisation is traditionally supposed to block sandhi, however both phenomena could co-occur [5]. The interplay between external sandhi and glottalisation has not been yet throughly investigated [5]. Regarding external sandhi in the non-native language, few studies have been dedicated to this topic so far and with conflicting results [6]. In order to investigate /r/-sandhi, we employ ultrasound tongue imaging. We recorded Southern British English native speakers reading English and German sentences. The sentences contained two-word-sequences, in which the first word ended with /r/ and the second word started with a low vowel, e.g. cider apples and jeder Abend (every evening in German). The second word (apples or Abend) was either accented or deaccented, and between the two words in the sequence there was either a phrase boundary or not, thus obtaining four possible sentence types. We hypothesise that glottalisation and external sandhi overlap is possible, and that external sandhi will be blocked by phrase boundaries, not by glottalisations. We expect that external sandhi will be most frequent in the deaccented, no-phrase boundary condition, and that glottalisation will be most frequent in the accented, phrase-boundary condition. Finally, regarding transfer to non-native productions we have two alternative hypotheses: a) English speakers will transfer their habits related to glottalisation and external sandhi from their native language to their non-native productions, or b) English speakers will separate words in their German speech, thus obeying to the “word integrity constraint” in the interlanguage suggested by [1], which “treats every word as a separate unit and prevents the articulatory synchronization of sounds belonging to different words” [1, p.19]. Preliminary results of the study will be presented at the conference. [1] Cebrian, Juli. 2000. Transferability and productivity of L1 rules in Catalan-English interlanguage. Studies in Second Language Acquisition 22(1). 1-26. [2] Cruttenden, A. and Gimson, A.C. 1994. Gimson’s pronunciation of English (fifth edition), revised by Alan Cruttenden. London: Edward Arnold. [3] Kohler, Klaus. 1994. Glottal stops and glottalization in German. Data and theory of connected speech processes. Phonetica 51. 38-51. [4] Dilley, L., Shattuck-Hufnagel, S. and Ostendorf,M. 1996. Glottalization of word-initial vowels as a function of prosodic structure. Journal of Phonetics 24(4). 423-444. [5] Scobbie, J., Pouplier, M. (2010). The role of syllable structure in external sandhi: An EPG study of vocalisation and retraction in word-final English /l/. Journal of Phonetics 38, 240-59. [6] Zsiga, E.C., 2011. External Sandhi in a Second Language: The Phonetics and Phonology of Obstruent Nasalization in Korean-Accented English. Language 87(2), 289-345.