Cool MateBut he sure is fast vs Certainly vs Definitely
When to use each in English, with meaning, register, and examples.
But he sure is fast
Top 3,000 (common)
Certainly
Top 1,000 (very common)A2adverb
Definitely
Top 1,000 (very common)A2adverb
| But he sure is fast | Certainly | Definitely | |
|---|---|---|---|
| Pronunciation | 🇬🇧 //bʌt hiː ʃʊə ɪz fæst//🇺🇸 //bʌt hiː ʃʊr ɪz fæst// | 🇬🇧 /["/ˈsɜːtnli/"]/🇺🇸 /["/ˈsɜːrtnli/"]/ | 🇬🇧 /["/ˈdefɪnətli/"]/🇺🇸 /["/ˈdefɪnətli/"]/ |
| Meaning | He is definitely quick. | Definitely; for sure. | For sure, without a doubt |
| Example | But he sure is fast when it comes to running. | Without treatment, she will **almost certainly** die. | I definitely remember sending the letter. |
| Register | Neutral | Neutral | Neutral |
| How common | Top 3,000 (common) | Top 1,000 (very common) | Top 1,000 (very common) |
| CEFR level | - | A2 | A2 |
| Part of speech | adverb | adverb | |
| Collocations | he sure is, but he, is fast | certainly agree, certainly possible, certainly not, certainly true, certainly yes | definitely agree, definitely believe, definitely know |
| Antonyms | - | uncertainly, doubtfully | doubtfully, uncertainly |
| Common mistakes | Using 'sure' without 'but' in a contrasting statement., Confusing 'fast' with 'quick' - they are similar but have different usages in context. | '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 in informal contexts, such as conversations or storytelling. Avoid in formal writing. | 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: But he sure is fast vs Certainly vs Definitely
What's the difference between But he sure is fast, Certainly, and Definitely?
But he sure is fast: He is definitely quick. Certainly: Definitely; for sure. Definitely: For sure, without a doubt
Can you show an example of each?
But he sure is fast: But he sure is fast when it comes to running. Certainly: Without treatment, she will **almost certainly** die. Definitely: I definitely remember sending the letter.
Can I use But he sure is fast, Certainly, and Definitely interchangeably?
Not always. But he sure is fast, 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.