The term assiduity can be pronounced in all sorts
of ways in General British (GB). It can be said as ˌasɪˈʤuːəti ~ ˌasəˈʤuːəti (more formally/in a slightly
old-fashioned way, also ˌasɪˈʤʊəti ~ ˌasəˈʤʊəti);
and without yod coalescence, in a more formal and old-fashioned manner, ˌasɪˈdjuːəti ~ ˌasəˈdjuːəti. (Even more
out-dated/formal are the renderings ˌasɪˈdjʊəti
~ ˌasəˈdjʊəti.) Other
completely out-of-date variants, which Alan Cruttenden would probably describe as
falling within what he has termed 'Conspicuous General British' (see Gimson's Pronunciation of English, 2014,
p. 81), have -ɪtɪ or -ɪti as the last two syllables, and æ in the first.
The
corresponding adjective, assiduous, can
be əˈsɪdjuəs (compressed, also əˈsɪdjwəs) or assimilated, əˈsɪʤuəs (also optionally compressed to əˈsɪʤwəs).
Unlike GB, in General American (GA) the only possibilities are əˈsɪʤuəs ~ əˈsɪʤ(ə)wəs for assiduous: yod coalescence in GA is compulsory if, within a word, the vowel after GB tj/dj is weak, i. e. u or ə. On the other hand, coalescent assimilations of the type tj → ʧ and dj → ʤ at the beginning of a stressed syllable before a strong vowel sound, albeit increasingly common in GB, are (still) considered as non-standard in GA. assiduity in GA is normally pronounced with yod-dropping, that is as ˌæsɪˈduːət̬i ~ ˌæsəˈduːət̬i (also, less commonly/more formally, ˌæsɪˈduːəti ~ ˌæsəˈduːəti). Variants with yod in the third syllable are also possible, though less frequent: ˌæsɪˈdjuːət̬i ~ ˌæsəˈdjuːət̬i (or again ˌæsɪˈdjuːəti ~ ˌæsəˈdjuːəti). See, for example, John Wells's Longman Pronunciation Dictionary (LPD), p. 52 and p. 843.
Unlike GB, in General American (GA) the only possibilities are əˈsɪʤuəs ~ əˈsɪʤ(ə)wəs for assiduous: yod coalescence in GA is compulsory if, within a word, the vowel after GB tj/dj is weak, i. e. u or ə. On the other hand, coalescent assimilations of the type tj → ʧ and dj → ʤ at the beginning of a stressed syllable before a strong vowel sound, albeit increasingly common in GB, are (still) considered as non-standard in GA. assiduity in GA is normally pronounced with yod-dropping, that is as ˌæsɪˈduːət̬i ~ ˌæsəˈduːət̬i (also, less commonly/more formally, ˌæsɪˈduːəti ~ ˌæsəˈduːəti). Variants with yod in the third syllable are also possible, though less frequent: ˌæsɪˈdjuːət̬i ~ ˌæsəˈdjuːət̬i (or again ˌæsɪˈdjuːəti ~ ˌæsəˈdjuːəti). See, for example, John Wells's Longman Pronunciation Dictionary (LPD), p. 52 and p. 843.
For some
unknown reason, and to my complete amazement, the Oxford Advanced American Dictionary Online
(OAAD) includes a pronunciation with -ˈʤu- (= -ˈʤuː-) for the term assiduity, which all the other
dictionaries I own or use frequently either don't acknowledge or rightly describe as non-GA. See the screenshot
below:
Those who
understand Italian can read what I say about the topic of this post on page 27
of my recently published book:
