(This may be interesting only to those of you who enjoy analysing
sounds and the difference between them, and why we say what we
say. But I thought it was fun.) :-)
It's been nearly two years, but I've finally figured out the
major difference between a Cameroon English accent and an
American English accent. Sure, people here pronounce their r's
differently, and their vowels are purer. But I think the major
reason that the two dialects have trouble understanding each
other is actually related to rhythm.
In American English (and most natively-spoken English, I think),
the stressed syllables are placed approximately evenly. This
means that some of our syllables (think "and the" or "of the")
are reduced to the minimum sound possible, and also means that we
ventilate our speech with brief pauses. This causes the
"lilting" feel of English.
Many other languages, instead of spacing their stressed syllables
evenly, space all syllables evenly. To Americans, this tends to
sound very rapid (think what a stream of Spanish sounds like to a
non-Spanish-speaker), and also occasionally gives the impression
of staccato regularity.
Cameroon English, borrowing its pronunciation from African
languages, uses the second system and not the first. Every
syllable receives its proper modicum of time. (For example: in
Cameroon English, "evening" has three syllables, all of the same
length.) When Cameroonians hear normal American English spoken,
they actually call it "rapping" because it sounds to them like
we're just rushing through our words without saying them
properly. Meanwhile, American ears that aren't used to Cameroon
English find the unexpected stress on (formerly!) unstressed
syllables distracting, and have their own difficulty in
understanding.
I may not be bilingual yet, but I think I'm at least becoming
bidialectal. :-)