Cool MateI don't think so vs Not that I know of
When to use each in English, with meaning, register, and examples.
I don't think so
Top 2,000 (common)
Not that I know of
Top 5,000 (fairly common)
Most common: I don't think so
| I don't think so | Not that I know of | |
|---|---|---|
| Pronunciation | 🇬🇧 //aɪ dəʊnt θɪŋk səʊ//🇺🇸 //aɪ doʊnt θɪŋk soʊ// | 🇬🇧 //nɒt ðæt aɪ nəʊ ɒv//🇺🇸 //nɑt ðæt aɪ noʊ ʌv// |
| Meaning | I disagree with that idea. | I don't have that information. |
| Example | Do you think we should cancel the trip? | Is there a new project starting next month? Not that I know of. |
| Register | Neutral | Neutral |
| How common | Top 2,000 (common) | Top 5,000 (fairly common) |
| Collocations | I don’t think so, I don’t believe so, I don’t feel that way | not that I know of, as far as I know, to my knowledge |
| Antonyms | I think so, Yes, Definitely | - |
| Common mistakes | Using it too aggressively in a polite conversation., Confusing it with 'I think not' which is more formal., Forgetting to tone down the response in sensitive discussions. | Using it in a context where certainty is required., Confusing it with 'not to my knowledge' as it feels less formal., Neglecting to use it when unsure if something is true. |
| Usage notes | Use this phrase in discussions to express your disagreement. It's neutral and can fit various contexts, but avoid in very formal settings. | Use this phrase when responding to questions about information you are uncertain about. It’s polite and straightforward, suitable for both formal and casual contexts. |
Frequently asked questions: I don't think so vs Not that I know of
What's the difference between I don't think so and Not that I know of?
I don't think so: I disagree with that idea. Not that I know of: I don't have that information.
Which is more common: I don't think so and Not that I know of?
I don't think so is the most common in everyday English.
Can you show an example of each?
I don't think so: Do you think we should cancel the trip? Not that I know of: Is there a new project starting next month? Not that I know of.
Can I use I don't think so and Not that I know of interchangeably?
Not always. I don't think so and Not that I know of 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.