Cool MateCertainly vs That's true
When to use each in English, with meaning, register, and examples.
Certainly
Top 1,000 (very common)A2adverb
That's true
Top 2,000 (common)
Most common: Certainly
| Certainly | That's true | |
|---|---|---|
| Pronunciation | 🇬🇧 /["/ˈsɜːtnli/"]/🇺🇸 /["/ˈsɜːrtnli/"]/ | 🇬🇧 //ðæts truː//🇺🇸 //ðæts tru// |
| Meaning | Definitely; for sure. | It is correct. |
| Example | Without treatment, she will **almost certainly** die. | She really loves painting, and that's true. |
| Register | Neutral | Neutral |
| How common | Top 1,000 (very common) | Top 2,000 (common) |
| CEFR level | A2 | - |
| Part of speech | adverb | |
| Collocations | certainly agree, certainly possible, certainly not, certainly true, certainly yes | that's true for, that's true about, that's true in |
| Antonyms | uncertainly, doubtfully | that's false, that's incorrect |
| 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. | Using 'that's truth' instead of 'that's true'., Confusing with 'that's truthfully'., Overusing in formal writing. |
| 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. | Used to agree with a statement. Avoid in overly formal contexts; prefer 'that is correct' instead. |
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Frequently asked questions: Certainly vs That's true
What's the difference between Certainly and That's true?
Certainly: Definitely; for sure. That's true: It is correct.
Which is more common: Certainly and That's true?
Certainly is the most common in everyday English.
Can you show an example of each?
Certainly: Without treatment, she will **almost certainly** die. That's true: She really loves painting, and that's true.
Can I use Certainly and That's true interchangeably?
Not always. Certainly and That's true 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.