Certainly vs Of course you are

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

Certainly

Top 1,000 (very common)A2adverb

Of course you are

Top 2,000 (common)
Most common: Certainly
 CertainlyOf course you are
Pronunciation🇬🇧 /["/ˈsɜːtnli/"]/🇺🇸 /["/ˈsɜːrtnli/"]/🇬🇧 //əv kɔːs juː ɑː//🇺🇸 //əv kɔrəs ju ɑr//
MeaningDefinitely; for sure.A way to say someone is right or true.
ExampleWithout treatment, she will **almost certainly** die.Are you joining us for dinner?
RegisterNeutralNeutral
How commonTop 1,000 (very common)Top 2,000 (common)
CEFR levelA2-
Part of speechadverb
Collocationscertainly agree, certainly possible, certainly not, certainly true, certainly yesOf course you are right, Of course you are welcome, Of course you are invited
Antonymsuncertainly, doubtfully-
Common mistakes'Certainly' is often incorrectly used in place of 'certain' in adjectives., Learners might confuse 'certainly' with 'definitely' without noticing the subtle nuance., Some learners use 'certainly' in inappropriate contexts, such as casual greetings.'Of course you are' can be confused with 'Indeed, you are' which is more formal., Some learners may use it sarcastically without realizing the tone., Learners might omit the 'you' and say just 'Of course' incorrectly.
Usage notesUse 'certainly' when you want to emphasize affirmation or agreement. It is more formal than 'sure' and works well in professional settings, but might feel too strong in casual conversations.Used to confirm someone's statement or belief. It’s friendly and supportive. Avoid in formal situations.

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Certainly
Of course you are

Frequently asked questions: Certainly vs Of course you are

What's the difference between Certainly and Of course you are?

Certainly: Definitely; for sure. Of course you are: A way to say someone is right or true.

Which is more common: Certainly and Of course you are?

Certainly is the most common in everyday English.

Can you show an example of each?

Certainly: Without treatment, she will **almost certainly** die. Of course you are: Are you joining us for dinner?

Can I use Certainly and Of course you are interchangeably?

Not always. Certainly and Of course you are 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.

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