Of course vs Oh i do

When to use each in English, with meaning, register, and examples.

Of course

Top 1,000 (very common)

Oh i do

Informal Top 2,000 (common)

Most formal: Of course Most common: Of course

	Of course	Oh i do
Pronunciation	🇬🇧 //əv kɔːs// 🇺🇸 //əv kɔrs//	🇬🇧 //əʊ aɪ duː// 🇺🇸 //oʊ aɪ duː//
Meaning	Definitely, it's obvious.	An expression of agreement or emphasis.
Example	Are you joining us for dinner tonight? Of course!	Oh, I do think that's a great idea!
Register	Neutral	Informal
How common	Top 1,000 (very common)	Top 2,000 (common)
Collocations	of course not, of course yes, of course you can, of course it is	Oh, I do agree, Oh, I do love it, Oh, I do understand
Common mistakes	Using it in formal writing where a different expression is needed., Confusing it with other affirmations like 'certainly' or 'definitely'.	Used in formal contexts where more standard phrases are expected., Incorrectly spelled or punctuated while texting., Confused with 'Oh I don't' to convey disagreement.
Usage notes	Used in informal and formal situations to affirm something obvious. Avoid in highly formal writing.	Used to show strong agreement or enthusiasm; common in spoken language, less so in formal writing.

See it in real clips

Of course.

Agatha Christies Poirot › S1 E1

You know her, of course.

And, of course, I paid my respect to Bubba himself.

Of course.

Agatha Christies Poirot › S1 E1

You know her, of course.

Of course

Avengers › Avengers Infinity War

Oh, I do.

Oh i do

Frequently asked questions: Of course vs Oh i do

What's the difference between Of course and Oh i do?

Of course: Definitely, it's obvious. Oh i do: An expression of agreement or emphasis.

Which is more formal: Of course and Oh i do?

Of course is the most formal of these.

Which is more common: Of course and Oh i do?

Of course is the most common in everyday English.

Can you show an example of each?

Of course: Are you joining us for dinner tonight? Of course! Oh i do: Oh, I do think that's a great idea!

Can I use Of course and Oh i do interchangeably?

Not always. Of course and Oh i do are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.