Experiences with different forms of T

[Amadeus]

I suspect that the definitions were once quite distinct but that the meaning became ambiguous because of misuse. In my experience, that's usually the case. It's why so many people now pronounce forte with two distinct syllables when they actually mean the one-syllable definition (as in, a strong point). People just misused it into common usage. The two-syllable version even appears in dictionaries now, much to my chagrin. "Biweekly" and "triweekly" are probably in the same boat.

I recommend to my students that they simply say "thrice weekly" (or "three times a week") or "every three weeks," depending on what they mean. But we should be able to use "triweekly" without any fear of misunderstandings!

A tricycle has three wheels, so it basically means "three wheels," not "a third of a wheel." So "triweekly" should basically mean "three weeks." But the adverbial form also throws in an additional monkey wrench, sigh.

I did not know these things.  Thank you.  I love learning about words and I try to keep up my grammar and spelling skills.