might still use . After American–British split, up to World War II This period is estimated to be c. AD 1725–1945. Split into rhotic and non-rhotic accents: syllable-final is lost in the English of England. The loss of coda causes significant changes to preceding vowels: merges with become (phonetically ) become long vowels, . All other short vowels plus coda merge as a new phoneme, the long mid-central vowel . Long vowels with a coda , , become new centering diphthongs, . Long vowels before intervocalic are also diphthongised, thus dairy from earlier . The Southern Hemisphere varieties of English (Australian, New Zealand, and South African) are also non-rhotic. Non-rhotic accents of North American English include New York City, Boston, and older Southern. Unrounding of : as in lot and bother is unrounded in Norwich, the West Country, in Hiberno-English and most of North American English The Boston accent is an exception where the vowel is still rounded. In North American English, is typically also lengthened to merge with in father, resulting in the father–bother merger: so that most North American dialects only have the vowel . Out of North American dialects that have unrounded , the only notable exception is New York City. The trap–bath split: in Southern England inconsistently becomes before and or followed by another consonant. Hence RP has pass, glass, grass, class with but mass, crass with . All six words rhyme in most American, Scottish English and Northern England English. The long vowels from the Great Vowel Shift become diphthongs in many varieties of English, though not in Scottish and Northern England English. Voicing of to results in the wine–whine merger in most varieties of English, aside from Scottish, Irish, Southern American, and New England English. In American, Canadian, Australian and to some degree New Zealand English, are flapped or voiced to between vowels. Generally, between vowels or the syllabic consonants , when the following syllable is completely unstressed: butter, bottle, bottom . But before syllabic is pronounced as a glottal stop, so cotton . Happy-tensing (the term is from Wells 1982): final lax becomes tense in words like happ. Absent from some dialects like Southern American English, Traditional RP, cultivated South African English and to some degree Scottish English. Line–loin merger: merger between the diphthongs and in some accents of Southern England English, Hiberno-English, Newfoundland English, and Caribbean English. H-dropping begins in England and