I'll let you know

USAGE SUMMARY

"I'll let you know" is correct and usable in written English
You can use it any time you want to tell someone that you will provide them with an update or answer to a question. For example: "I'm not sure what time the bus leaves. I'll let you know as soon as I find out."

✓ Grammatically correct

News & Media

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

YOU: I'll let you know.

The New Yorker

Again, I'll let you know.

Independent

And I'll let you know".

The New York Times

I'll let you know asap.

The Guardian - Sport

I'll let you know tomorrow.

The Guardian - Music

If I do, I'll let you know".

The New Yorker

I'll let you know what I find.

The New York Times

I'll let you know for sure".

The New York Times - Sports

I'll let you know about it.

The New Yorker

It's very difficult, I'll let you know".

The New York Times - Style

I'll let you know when something happens.

The Guardian - Sport

Expert writing Tips

Best practice

Use "I'll let you know" when you genuinely intend to provide an update. Avoid using it as a brush-off.

Common error

While common, relying too heavily on "I'll let you know" can make you sound noncommittal. Vary your responses with more specific promises of action, like "I'll email you the report by Friday" or "I'll get back to you" by tomorrow.

How to use

Learn how to use "I'll let you know" with practical examples and tips.

How to use

Linguistic Context

The primary grammatical function of "I'll let you know" is to serve as a promise or assurance that the speaker will provide information to the listener at a later time. Ludwig AI validates its correctness and usability in written English.

Expression frequency: Very common

Frequent in

News & Media

100%

Less common in

Formal & Business

0%

Science

0%

Academia

0%

Ludwig's WRAP-UP

"I'll let you know" is a very common and grammatically correct phrase used to assure someone that you will provide them with information or an update later. Ludwig AI confirms its validity and broad applicability. While suitable for various contexts, from news to casual conversation, it's essential to use it genuinely and avoid overuse. Consider alternatives like "I'll keep you informed" or "I'll get back to you" for variety and specificity. To enhance clarity, specify a timeframe for your update.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

I'll get back to you

Specifically indicates a response to a question or request will be provided.

I'll keep you informed

Implies a more continuous provision of updates, suitable for ongoing situations.

I'll keep you posted

Similar to 'I'll keep you informed' but slightly more informal.

I'll inform you when I have more information

More formal and explicit about the condition for providing the information.

I'll notify you

A more formal and direct way of saying someone will be informed.

I'll update you later

A more general and less committal way of promising future information.

I'll give you a heads-up

Informal, suggesting a warning or preparation for something.

I'll be in touch

A less specific commitment to provide particular information, indicating general communication.

I'll advise you

Suggests providing guidance or a recommendation, not just information.

I'll communicate with you

Emphasizes the act of communication rather than the specific information.

FAQs

When is it appropriate to use "I'll let you know"?

Use "I'll let you know" when you plan to provide information or an update to someone at a later time. It's suitable when you don't have the information immediately available but intend to find it out and share it.

What are some alternative ways to say "I'll let you know"?

Depending on the context, you can use phrases like "I'll keep you informed", "I'll get back to you", or "I'll update you later".

Is "I'll let you know" formal or informal?

"I'll let you know" is generally considered neutral and can be used in both informal and professional settings. However, in very formal contexts, a more precise statement might be preferable.

How can I make "I'll let you know" sound more proactive?

Instead of just saying "I'll let you know", add a specific timeframe or action. For example, "I'll research that and "I'll get back to you" by the end of the day" sounds more committed.