Oh is one of those words you can pair up with other words to make different meanings. Recently, one author gained some notoriety for how many times she used the phrase "Oh my" in her book. In that case, the character was often expressing disbelief in regards to the strange new relationship she had begun with a man and the new things she was experiencing.
Oh can also be used by itself. "Oh that was fun" or "Oh for heaven's sake." In these cases, it is often used to express a little surprise at what was said or just happened. It can also be an expression of dismay or disapproval. "Oh for the love of Pete!"
Sometimes, Oh isn't even a word, but more like a sound. Oh Oh Oh. I'll leave that one to your imagination, but keep your mind out of the gutter please, this is a family friendly blog.
As a writer, I sometimes let my characters use the word Oh. It fills in when you don't have a suitable word to acknowledge a statement without actually agreeing with it, or disagreeing for that matter.
"That was different," Cindy said.
"Oh." Tony replied. He didn't think it was different at all, but realized that for Cindy, it was completely new.
Musicians and song writers seem to love the word Oh almost as much as I do. Kashmir by Led Zeppelin comes to mind right away. Robert Plant croons the word many times in that eight-minute-plus work of musical genius. It wasn't the only song he sang or wrote that used the word, and in fact, that word probably takes up pages of definitions in the rock and roll dictionary.
Oh, and it probably means as many different things to anyone who hears it as it does to the songwriters that included it in their lyrics.
Did I just do that? I did, didn't I. Oh Well.
Ha. I remember a kid who used a certain phrase so often, I often associated it with him whenever I saw him. "Oh well, such is life." He could say it sarcastically, or meaningfully, or even with no inflection at all, which often sounded even more sarcastic.
I see it in poetry too, often in a lament or sad way. Rarely in surprised or happy verse.
Oh the sad song of life,
drifts along the gentle breeze,
and takes its calling to the grave.
But still, of all the things you can do with Oh, there is nothing more satisfying than surprising someone with news that you know will shock them, and seeing the look on their face and hearing their surprised expression, "Oh!" as their face freezes in that position for a few seconds, forming a big "O" with their lips.
All I can say is, "Oh Yeah."