Jack Windsor  Lewis has sent a comment to my post on “two names and a word” which dealt with an unusual pronunciation of sedentary:

This morning, 28 Dec 09, also on Radio 4 but on Andrew Marr’s ‘Start the Week’ discussion programme, I he’rd Cambridge Professor of Neuroscience Barbara Sahakian, use the stressing ef`ficacy inste’d of the usual front stress which is the only one recorded in the three big pronouncing dictionaries and in M’Webster Online. Her speech sounds int’restingly slightly transatlantic. The Internet gives no info on her speech-formative years. I’ve no definite memory of hearing it so stressed before but I think I have he’rd the also unrecorded in`tricacy.

I don’t think I’ve ever heard ef’ficacy before, although it doesn’t surprise me (but maybe it does in someone so well educated as Professor Sahakian). Like Jack, I have heard in’tricacy. These are yet more examples of words taking on an antepenultimate stress pattern, perhaps in order to avoid three unstressed syllables in a row. They follow the pattern of con’troversy, frag’mentary, tra’jectory (which I am old-fashioned enough to still pronounce ‘trajectory – although I do split infinitives!) All these have changed, or are in the process of changing, from initial to second-syllable (= antepenultimate in these cases) stress.

John Cowan commented on my “sedentary” post that in the US, the -ary suffix of sedentary and fragmentary does not reduce to /-əri/. In the words that I was assuming it was being stressed by analogy with – elementary, complimentary, even US English reduces -ary to /-əri/, so this would not be a bar to the stress pattern changing in American accents as well. One more example among many of the conservatism of US English (that’s not meant as a criticism, by the way).