This is interesting. I'm a JC Comp Honor's student, so this is right up =
my alley. And I have a copy of the AH Dictionary and an old copy of the =
MLA handy, so here goes:
bi=B7an=B7nu=B7al (b-ny-l) "bi-annually" [P] adj.
- Happening twice each year; semiannual.
- Occurring every two years; biennial.
This source cited from MLA: "bi-annually." The American Heritage=AE Dictionary of the English=20 Language, Fourth Edition. Houghton Mifflin Company, 2004. 03 Nov. 2006.=20
So, it appears that the term "semiannual" refers to an occurance 2X/yr.=20 Biennial refers to an event that happens every 2 years. And finally,=20 the term "bi-annual" can refer to either term.
"bi-annually" refers to an event that occurs twice a year, to wit:
biannually adv : twice a year; "we hold our big sale biannually" (cited from same source)
So, technically, when I say that change the coolant bi-annually, it=20 refers to a change that occurs two times per year.
Class dismissed. And yes, I take good care of my horse. I'll probably=20 keep it forever, so don't get any ideas!