When the exclamation Oh’ appears in a conversation, it is a reflection of the following: sadness, annoyance, surprise, or disappointment. So, as you reply you should factor in the emotions and feelings of the person using it.
A response to Oh should address the feelings triggered in the other person. For example, if you are going to be late: “I’m very sorry about that too, an important call came up that I couldn’t turn down.”
Here is a breakdown of how to reply depending on the different emotions.
When a person is sad, you don’t expect them to be at their best. They are likely to utter words that you may not like. Also, their emotions are not at their best. If you’re conversing with someone about a sad topic, it’s likely that they may use the word oh’ in the process. How do you respond in such a situation?
Generally, most people don’t appreciate that word. They see it as a rude way of expression. However, it’s important to evaluate the situation and establish why a person chooses to use the word. According to a ResearchGate article, context is significant when communicating with someone. 
In the context of a sad person, it’s advisable to acknowledge their situation and respond in a way that doesn’t increase their level of sadness. For example, you could be talking to your friend and tell him about a mutual friend who got sick.
Of course, he will receive the news with sadness. The conversation can be something like this:
“I went to visit Keith the other day and found him very sick. He could not move from his bed.”
Then, upon listening to you he answers with an oh’. At first, someone may not like the usage of the word oh’ as it appears as putting a stop to the conversation. However, in this situation, it is important to understand that this person is sad about the sick friend and may not know how to react.
In this situation, it’s best to reply by encouraging the person and being positive about the issue.
For example, you can say something like:
“The doctor said he will feel better after taking medication for a week or so.”
Someone can also use the exclamation oh’ as a result of annoyance. You could be having a conversation with someone and, in the midst of the conversation, he happens to get annoyed. It could be something you say that doesn’t please him.
At this point, people may actually feel distant from the conversation as they reflect on their annoyance. You may or may not notice that the other person gets annoyed by what you say. So, instead of the person listening to what you’re saying and responding well, he chooses to utter the word oh’.
A good example is this: “When I was coming I thought you wouldn’t be interested but I chose to come anyway.” The person you’re talking to can get offended by the way you thought about him, such that anything else you say doesn’t matter to him. So, instead of responding positively, he only responds with a cold oh’.
It’s like asking, do you think I am not interested? How do you respond in such a situation?
Your reply should show the person that you didn’t mean to annoy him. If you didn’t have the intention of annoying him, it’s prudent to demonstrate that through the words you use in your reply.
Once you have successfully done that, you can continue with the conversation.
Someone can also use the word oh?’ as a sign of surprise. If you’re having a conversation with someone and you happen to say something that is a surprise, it’s possible for them to react in such a way.
For example, if you’re chatting with someone and you send a message that’s surprising, the reply can come in the form of an oh?’ If this isn’t a response you were expecting, you may not know how to reply back.
You may send a message like: “Mary decided never to come back after the bitter disagreement” then the person you’re sending the message to replies with oh?’ If you were expecting the person to know what you’re talking about and to send you a more meaningful reply, you’ll feel confused as to how to reply to the text.
Clearly, this shows that the person gets surprised by the message. For that reason, your reply should try to bring the person to a point of understanding what you’re talking about.
The reply to the exclamation could be something like:
“I can see you’re surprised”.
This will help trigger further conversation where you’ll be able to talk about the issue at a deeper level.
Lastly, someone can choose to use it to show disappointment. Whether it is in written or oral communication, you can tell whether a person uses it to express disappointment. The best way to assess whether a person exhibits disappointment or not is by looking at the context of a conversation.
For example, if you had agreed with your friend that you’ll meet in the evening and you send him a text message telling him that you won’t make it, he may respond by sending you the oh?’ exclamation. Certainly, this shows the disappointment of the person for failing to keep your word.
As you reply, you’ll respond knowing that there is a level of disappointment for breaking a promise.
“I know, I’m really sorry about that too. I had tried everything, but the project must be ready by tomorrow morning.”
It is also important to point out that the tone a person uses speaks volumes. Be sure to listen to the tone a person uses when using the word oh?’ This should give you a good idea of how they feel. If a person is disappointed, the tone they use will definitely give you an idea of how to reply to them. Therefore, get to understand the emotions of a person after using the expression oh?’ to know how to reply appropriately.
Sophie Hammond is a journalist, psychologist, and freelance speechwriter for people in politics and business. She lives on the edge of the Rocky Mountains with her dog and a lifetime supply of books. When she’s not writing, she can be found wandering through nature or journaling at a coffee shop.