
Once again this variation is to be assumed.

(iii) Though the widely received pronunciation of words like which and why is with a simple /w/ sound and is so shown in the dictionary, many speakers in Scotland and elsewhere preserve an aspirated sound: /hw/. Again such variations are to be assumed, and in such words as fern, fear, and arm the reader will sound or not sound the ‘r’ according to his or her speech habits. However, many speakers in other areas do sound the ‘r’ in such positions with varying degrees of distinctness. (ii) The letter ‘r’ in some positions is not sounded in the speech of Southern England and elsewhere. Such variations are acceptable and are to be assumed by the reader. (i) Though words like castle, path, and fast are shown as pronounced with an /ɑː/ sound, many speakers use an /æ/. In photographic (,fəʊtə’græfɪk), for example, the first syllable carries secondary stress and the third primary stress. Primary or strong stress is shown by ‘, while secondary or weak stress is shown by. Three grades of stress are shown in the transcriptions by the presence or absence of marks placed immediately before the affected syllable. The symbol ː denotes length and is shown together with certain vowel symbols when the vowels are typically long. The remaining symbols and their interpretations are listed below. The following consonant symbols have their usual English values: b, d, f, h, k, l, m, n, p, r, s, t, v, w, z. The symbols used in the pronunciation transcriptions are those of the International Phonetic Alphabet.

IPA Pronunciation Guide – Collins English Dictionary
