Cool MateCertainly vs Definitely
When to use each in English, with meaning, register, and examples.
Certainly
Top 1,000 (very common)A2adverb
Definitely
Top 1,000 (very common)A2adverb
| Certainly | Definitely | |
|---|---|---|
| Pronunciation | 🇬🇧 /["/ˈsɜːtnli/"]/🇺🇸 /["/ˈsɜːrtnli/"]/ | 🇬🇧 /["/ˈdefɪnətli/"]/🇺🇸 /["/ˈdefɪnətli/"]/ |
| Meaning | Definitely; for sure. | For sure, without a doubt |
| Example | Without treatment, she will **almost certainly** die. | I definitely remember sending the letter. |
| Register | Neutral | Neutral |
| How common | Top 1,000 (very common) | Top 1,000 (very common) |
| CEFR level | A2 | A2 |
| Part of speech | adverb | adverb |
| Collocations | certainly agree, certainly possible, certainly not, certainly true, certainly yes | definitely agree, definitely believe, definitely know |
| Antonyms | uncertainly, doubtfully | doubtfully, uncertainly |
| 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. | Often confused with 'defiantly' which means resisting authority., Sometimes spelled incorrectly as 'definately'. |
| Usage notes | Use '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. | Use 'definitely' to emphasize certainty. It fits well in both spoken and written English. Avoid using it in overly formal contexts where alternatives like 'certainly' might be more suitable. |
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Frequently asked questions: Certainly vs Definitely
What's the difference between Certainly and Definitely?
Certainly: Definitely; for sure. Definitely: For sure, without a doubt
Are Certainly and Definitely the same CEFR level?
Certainly: A2, Definitely: A2 on the CEFR scale.
What part of speech are Certainly and Definitely?
Certainly: adverb, Definitely: adverb.
Can you show an example of each?
Certainly: Without treatment, she will **almost certainly** die. Definitely: I definitely remember sending the letter.
Can I use Certainly and Definitely interchangeably?
Not always. Certainly and Definitely 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.