Biweekly, bimonthly, semi-confused [closed]

Solution 1:

The obvious distinction is between biannual and biennial which although originally cognate from Latin and Italian now seem to have distinct common meanings: twice a year and every two years respectively, even though Wiktionary discourages biannual.

So for weeks and months all you need to do is wait for two forms to arise and then wait for people to decide which is which. Semi- for "half a ...", i.e. "twice a ...", looks a sensible approach.

Solution 2:

Looking at the prefixes, bi means two, and semi means half. But the question here, is does that refer to the number of occurrences in the given period, or the number of periods per occurrence? I think that's where the confusion came in, and apparently the coiners of the words were not consistent.