Oh, did I interrupt your morning with my insignificant blabber? I might have, but if you read on you might just find something interesting to light up your day.
Perhaps the least explored commonly used word in English language, “Oh” is frequently used in conversation whether informal or formal. It’s an important element in a conversation that provides nuance for you to understand better what one is trying to convey. Without it one could miss out the most important cue in a message.
Consider this, “I think it was blue or red. Oh I am wrong. It’s red.” If you omit “oh” in this conversation you might end up sounding either too robotic or less humble. The risk of not using “oh” is that the meaning of your gesture would be greatly misunderstood, and may even sound argumentative. Yes it might be a speech crutch to a toastmasters member, but having “oh’s” in your conversation, like your mother used to say, would give you much character.
Let me list down the various functions of “oh” in our day-to-day conversation.
1. Correcting someone else : A said “Well that was a beautiful fish” B correcting A “oh that was actually a mammal”
2. Requesting clarification: A said “Is there anyone you would like to talk about?” B replied “oh you mean now?”
3. Suddenly remembered question “Oh listen I forgot to ask you….”
4. Knowledge re-orientation: A said “How can I get an appointment to go down there to bring my son on a tour?” B replied “Oh I didn’t even know they gave tours”
5. Unanticipated Information: “Oh I didn’t know that!”
6. Display of recognition: A said “We ate at the Shanty Seafood” B replied “Oh yeah, I’ve heard that’s good”
7. Receiving new information: A said “Hey Henry, your girlfriend’s here” B answered “Oh yeh?”
8. Make an intense reaction: A said “SM Kepong still has a reputation” B responded “But like it did?”, A instantly interjected “Oh yes, SM Kepong is still rated higher than SM Taman Ehsan”.

“Look at that BIG ang pow my boss has in his pockert, oh did she just snap the digital camera without my knowledge?!!”
A special thanks to The Cambridge Encyclopedia of The English Language written by David Crystal.