Following from last week’s post, here’s another interesting word where minute changes in phonetics and spelling make for an interesting look at EP vs. BP differences. I’m talking about [o] metro, which is the common abbreviation of [o] metropolitano, metro/subway (I did tell you I was a fan of trains!).
In Brazil, the word is turned into [o] metrô – just like sumo/sumô from last week. I believe this change occurred to better match its pronunciation with the equivalent syllables in the word metropolitano from which it derives.
A more thorough explanation of the phonological processes at play we show up after the jump! (It has a really nice vowel chart and coloured arrows! You should really check it out!)

In EP, metropolitano and metro have different sounds on the first vowel:
- [o] metropolitano: [mətru]puliˈtɐnu
- [o] metro: ˈmɛtru

The fact that the vowel sound [ə] is never present on a stressed syllable helps explain this difference between the two (it is used in metropolitano because it’s not the stressed syllable, it can’t be used in metro because there “-me-” is the stressed syllable); the existence of a prexisting word with this spelling – [o] metro (meter, unit of length) – helped settle the matter over which of the possible stressed forms of e [ɛ / e] to use.
BP also used the word [o] metro for meter, but practice and the phonetic structure of the language caused this change to occur (especially the fact that it is much more syllable-timed than EP, not relying on stress so much, which makes it able to mimic the original sounds of the word metropolitano in its abbreviation).