I enabled the Locale module and imported the Afrikaans .po file. This went well. However, when I tried to do the same for the Spanish translation, there's a .po for every module, theme, and profile. I wonder if there's an easier way to do this than importing each one separately. Also, when I switched back to English as the default language, I have some Spanish straggling terms still hanging out in the toolbars. Hmmm, this will need some more testing and investigation to implement, I think.

I think maybe parts of the toolbars are hanging on because I imported a couple .po's and they overrode the English settings? I don't know, but I'll keep an eye on it.

UPDATE: I logged out of admin and logged back in, and I enabled the Content Translation module and now everything is back to English. I'm not sure which of these variables solved the problem, or if it just needed time to go back to English. I'll keep my eyes open.