Okay, so we seem to have established (with lots of great and generous help from StoneyB and Peter Shor) that:
- where it came to certain diphthongs, Shakespeare either elided syllables that didn't fit into the line, or didn't, depending on the situation. (Specifically, we went over some words ending in -ious, but there are others, such as the word continually, which Shakespeare treats (in Richard III) as if it only had four syllables, not five).
- that such "extra-metrical" (a term used by Robert Bridges in his long essay on John Milton's prosody) syllables are always unstressed (duh).
- that the contemporary ear will accept some of those elisions, but might at the same time protest against others; i.e. should someone write and stage a play in verse today, he or she could treat such words as ceremonious as if they had four syllables rather than five without worrying that someone might accuse them of having written a silly-sounding Shakespearean pastiche.
- that the reason some words resist such eliding (the word curious is three syllables; it can't be shortened to two, ever, full stop) SEEMS to have something to do with the consonant preceding the vowel in the unstressed syllable slated for elision. I tentatively proposed that "r" may be one such consonant.
My question, then, goes like this. Is there a rule or pattern that would enable one to create two lists of words: the first one consisting of words that can be shortened through elision; and the second one of words that can't.
Any and all answers will be greatly appreciated.