15 Other Ways to Say I Don’t Know

I don’t know is a phrase often used when you are asked a question and do not have an answer or are uncertain about something. There are many synonyms you can use in its place.

A formal alternative is I can’t say for certain.

• The clients should arrive in an hour, but I can’t say for certain.

A casual alternative is I dunno.

• I dunno why she’s in such a bad mood.

What Does I Don’t Know Mean?

The phrase I don’t know indicates that you don’t have an answer to a question or that you are uncertain about something. It’s a common response when someone asks you a question to which you don’t have enough (or any) information to answer.

I don’t know, is a phrase frequently used in various settings throughout the day. It can be heard in casual conversations with friends, brief encounters with strangers, classroom discussions, business meetings, and other situations.

However, if you want to express yourself fluently, you should become familiar with a few other phrases that are similar to I don’t know. That’s why we’ve compiled a list of I don’t know synonyms that you can use in professional or casual settings.

Let’s begin!

I Don’t Know Synonyms: Formal Alternatives

As we already mentioned, the phrase I don’t know is used in various settings. However, saying I don’t know in a professional context, such as a meeting with your boss, can make you seem unprepared or uninterested.

Of course, there will be times when you do not know something, but there are stronger alternatives you can use in place of I don’t know.

1. I’m not certain, but I can find out for you.

2. I’m not entirely sure, but I believe …

3. I’m not the best person to ask, but perhaps [name of colleague/expert] might know.

4. That’s a good question. Let me do some research and get back to you.

5. I would need to do some research before giving an accurate response.

6. I don’t have a definitive answer, but I’ll look into it and get back to you.

In the list of synonyms for I don’t know provided above, you’ll notice that they include actionable steps. While these phrases indicate that you do not have the information required to answer a question, they also convey a willingness to find out. This can be a positive trait, especially when dealing with superiors in the workplace.

However, sometimes the most appropriate response is I don’t know. In those cases, instead of using that exact phrase, you can convey a similar message more tactfully with the following alternative:

7. I can’t say for certain.

There are many ways to say, “I don’t know.”

I Don’t Know Synonyms: Casual Alternatives

Perhaps you want to say I don’t know more fluently or colloquially. In that case, you don’t have to put too much thought into actionable steps.

Instead, you can just use any of the alternatives below. They express that you don’t have all the information needed to answer a question, but in a manner that is less formal or serious.

8. I dunno.

9. Beats me.

10. I have no clue.

11. Your guess is as good as mine.

12. No idea.

13. Who knows?

“I Don’t Know”: Be Confident in Uncertainty With LanguageTool

Next time you’re uncertain about something, or you don’t know the answer to a question, you’ll be able to express yourself confidently with the I don’t know synonyms listed above.

Familiarizing yourself with alternatives to commonly used phrases is a great way to improve your English fluency. LanguageTool—a multilingual writing assistant—makes the process even easier by helping you rephrase your sentences.

Dunno if it’ll work for you? Try it out!