摘要:In this paper, the contexts that block vowel merger and vowel deletion in BrazilianPortuguese and European Portuguese are analysed. It aims at identifying differences and similaritiesbetween BP and EP, which may be related to their rhythmic and prosodic organization. Therefore,speech data were collected for BP following the methodology employed by the research done byFrota (1998) for EP. Comparing BP and EP, we found that in both of them there are (i) rhythmicrestrictions that block ill-formed rhythmic configuration at phrase phonological level; (ii) a directionalhead-effect which is related to the restriction that preserves the prominence of rightmost stress withinthe phonological phrase; (iii) active restrictions that depend on the type of phonological process andof prosodic structure in which sandhi contexts are found. What makes BP differ from EP is the factthat vowel merger and vowel deletion are blocked depending on V1/V2 distinction and prosodicprominence.