Oh ͜ 

1 At the beginning of a statement, pronounced in rapid succession with the next word and unstressed, Oh is used to turn a statement of fact into an assurance, with a nuance of «don't worry...» in the sense of «you can be sure»

For instance, in this snippet, the father says Oh I did, meaning Don't worry — I already did. And this doesn't refer to a literal "worry" — it's more like «You can be sure!».

Intonation and rhythm are key here; the reassuring oh is short, unstressed and leads right into the next word with no pause. For instance, in the context of the following snippet, if the oh were stressed, it would sound like Alex just remembered the money when his daughter mentioned it; he had forgotten to tell her he'd already spoken to his wife, and the daughter just reminded him when she brought it up. 

Listen to the difference: 

Oh I díd. «Don't worry, I already did.»

Óh, I díd. «Thank you for reminding me! I already did it.»

Alex: Dad, don’t forget to tell mom I need $50 for next week’s school trip.

Dad: Oh I did. I told her this morning. She says she’ll give it to you tonight.

In this cartoon, the guy assumes the dog is waiting for its dead owner to come back, but the dog uses oh to assure him that he's doing no such thing — he's just there to remember the times he had with his owner.

2a Sometimes, the reassuring tone of oh is used to express smugness. 

For instance, in this snippet below, Fred's oh has a very smug quality. You can picture him smiling smugly with his arms crossed. He's not only telling his wife he already knows about the party, but in using this oh, he's expressing a sarcastic assurance, preparing his wife for the bombshell that her friend, Barbara, isn't as discreet as his wife thinks. 


This type of reassurance can also be expressed by the phrase Don't worry,... which, in this usage, doesn't literally mean "don't worry," but rather «you can be sure of this». So, in the snippet below, Fred could also have said "Don't worry — I know." 

Fred walks into the kitchen and finds his wife cooking up a storm.


Wife: Fred, I’m throwing a surprise party for your sister next weekend. But don’t tell anyone — nobody knows about it except you, me, and my friend, Barbara. But she won’t tell anyone.

Husband: Oh I know.

Wife: You know about the surprise?

Husband: Oh yeah.

Wife: How??

Husband: Your friend, Barbara, told me.

2b The smugness expressed by Oh and described in 2a can be made more emphatic, authoritative and even forceful by adding all right (also spelled alright) at the end of the statement. 

Here, the nuance of «don't worry» becomes a more emphatic «Don't you worry!» or even «You can be (damn) sure of that!». Note that all right is pronounced with a low intonation.

This expression is often used to turn what sounds like a guess into an absolute assurance. For instance, in this snippet, Carla hints at the fact that Cooper and Sandy might be in a relationship, and then Nancy removes all doubt by using the phrase Oh... all right. 
_________________⦿ lovey-dovey | very romantic — especially in a corny way⦿ if I didn't know (any) better, I'd swear/say... | Used sarcastically to act as if something isn't glaringly obvious when it's happening right in front of your face.⦿ to make out | to kiss very passionately for an extended period of time

Carla and Nancy notice a strange, lovey-dovey dynamic between their manager and a female coworker during a meeting.


Carla: Have you noticed how Sandy looks at Cooper during meetings. If I didn’t know better, I’d swear they were together.

Nancy: Oh they’re together all right — I saw them making out in the parking lot this morning before work.

This all right is often used is when someone is being authoritative and throwing someone's words back in their face as an absolute assurance. For instance, here, Danny says he's going to bring his grades up, and his father assures him that that's exactly what he's going to do, using the formula Oh... all right.

Nicky and Natasha are looking at their son Danny's report card and can’t believe he’s barely passing Spanish. 


Nicky: What’s this, a C in science? A D in Spanish? That was your best subject last year. 

Natasha: That’s because he plays basketball with Alex every day after school and then bangs out his homework as fast as he can so he can play video games.

Danny: Sorry! I’ll bring my grades up!

Nicky: Oh you’re going to bring your grades up all right… you’re going to come straight home after school every day and do your homework, AND I’m getting you a Spanish tutor.

3 Unstressed Oh is commonly used in front of something you want to play down or make sound less important or even unimportant in order to sound humble and unassuming.

The humor in this meme lies in the fact that someone has obviously just asked this guy how he stays in such good shape. In response, he flexes his right arm to show off his biceps, while making a humble, dismissive, waving motion with his left hand to play down his exercise routine (obviously, nobody gets that kind of physique by just "jogging every once in a while".) Here, the initial Oh just complements the dismissive gesture and makes his response sound even more humble.

4 In front of a command, Oh is used to express impatience and frustration.

In this usage, it's always used with just (also unstressed). 

In this meme, the speaker is so tired of reading stupid Facebook statuses that he feels like telling the author to just shut up! He feels like he can't read one more.

Brad is visiting his brother for the weekend.


Brad: Can I have the wifi password?

Jimmy: It's my birth year...

Brad: 2009

Jimmy: Plus my house number...

Brad: Oh just give me the password already!