In having a conversation with some friends, I noted that I decided at one point to forgo an option that I had at hand. Since I was speaking in the past, I had to put it in the correct tense. I knew the word "forgo", and had heard about "forgone" conclusions, but had never seen "forgo" in the past tense. Being a native English speaker, I paused for a split second to take a stab at the best option which seemed to fit, and therefore explained that I had "...forwent" the option. A quick check in the dictionary later showed that my instincts were correct. (Little happy dance here).
That would have been the end of it, except that sometime later I was watching a report on skydiving, mentioning that some of the participants "skydived" a few times in the past.
Now I was confused. Skydived? Why not "skydove"? Makes perfect sense. I know that "dived" is a valid past tense alternate, but "dove" is certainly the more preferred usage as a simple past. It seems to me that here we do not use the formula of [for] + [go, p.t.] = [forwent]. It is being conjugated not as [sky] + [dive, p.t.] = skydove, but instead that [skydive] has become inseparable and should therefore be conjugated as "skydived."
The first part of my question is: what determines the rules as to whether one should be conjugating the compound as a single word (most likely with +ed), or if the verb part should be separated and conjugated by itself?
The second part is to ask if people can come up with additional examples of other such compound words, some where the verb is conjugated separately and others where the compound has made its way into the language as an inseparable case?
Much obliged, Questor