[Urbane Guerrilla]

What truly marks the foreigner speaking English is the vowels. Somebody raised in a language that is mainly pure vowels needs either long experience and an acute ear, or else detailed instruction, to deal with English's diphthongal glides. English has few pure vowels; they are most often either iotized or they are mainly one vowel with a faint tail of another, e.g. the English long "O" finishes up with a tiny "U" at its end, and conversely trying to get English speakers to deliver a pure "O" sound European-style can be quite the struggle -- they don't necessarily hear that U tail-off because we think long O is one sound.