Formal vs Casual Ways to Say ‘Let me know’

The phrase “let me know” is a standard way to ask for information or a decision, but it can sound too direct or vague depending on who you are talking to. In formal settings, you need more polite and specific phrasing, while in casual situations, shorter and more relaxed versions work better. This guide gives you direct alternatives for both situations, with examples you can use immediately in emails, conversations, and workplace messages.

Quick Answer: Choose Your Version

• Formal: “Please advise,” “I would appreciate your input,” “Kindly inform me,” “I look forward to your response.”
• Casual: “Keep me posted,” “Give me a shout,” “Just tell me,” “Hit me up.”
• Neutral (works in most situations): “Please let me know,” “I’d like to hear your thoughts.”

Comparison Table: Formal vs Casual Alternatives

When to Use Formal Versions

Use formal alternatives when writing to a client, a senior manager, a professor, or someone you do not know well. Formal language shows respect and professionalism. It also makes your request clearer and more polite.

1. “Please advise”

This is a common formal phrase used in business emails. It is short but polite.

Example: “Please advise on the next steps for the project.”

Nuance: This works well when you need a decision or direction. Avoid using it in very casual conversations because it can sound stiff.

2. “I would appreciate your input”

This phrase is softer and shows that you value the other person’s opinion.

Example: “I would appreciate your input on the draft before I send it to the client.”

Nuance: Use this when you are asking for feedback or suggestions, not just a yes/no answer.

3. “Kindly inform me”

This is very formal and polite. It is often used in official letters or formal emails.

Example: “Kindly inform me of the deadline for the submission.”

Nuance: This can sound old-fashioned in some workplaces. Use it only in very formal contexts, such as legal or academic communication.

4. “I look forward to your response”

This is a standard closing line in formal emails. It is polite and professional.

Example: “I look forward to your response regarding the proposal.”

Nuance: This works best as a closing sentence. Do not use it in the middle of a message.

5. “Your guidance would be helpful”

This is a respectful way to ask for advice or direction.

Example: “Your guidance would be helpful as I prepare the report.”

Nuance: This is ideal when you are unsure and need someone more experienced to guide you.

When to Use Casual Versions

Use casual alternatives with friends, close colleagues, or in informal group chats. These phrases are shorter and friendlier.

1. “Keep me posted”

This is a common casual phrase that means “tell me when you have news.”

Example: “Keep me posted on what the team decides.”

Nuance: This works well in both spoken and written informal communication. It is not rude, but it is not appropriate for formal emails.

2. “Give me a shout”

This is very casual and friendly. It means “contact me when you know something.”

Example: “Give me a shout when you are free to talk.”

Nuance: Use this only with people you know well. It can sound too informal for a new colleague.

3. “Just tell me”

This is direct and can sound impatient if used incorrectly. Use it when you are close to the person and the topic is simple.

Example: “Just tell me what you need from me.”

Nuance: Be careful with tone. If you say it too bluntly, it can sound rude. Add a smile or a friendly tone in conversation.

4. “Hit me up”

This is very informal and common among younger speakers or in text messages.

Example: “Hit me up when you get the details.”

Nuance: Do not use this in any professional setting. It is only for close friends or very casual groups.

5. “Let me know when you can”

This is a neutral casual phrase that is still polite. It gives the other person flexibility.

Example: “Let me know when you can check the file.”

Nuance: This is a safe choice for most informal situations. It is not too casual and not too formal.

Natural Examples in Context

Formal Email Example

Subject: Request for Feedback on Marketing Plan
Dear Ms. Chen,
I have attached the draft marketing plan for your review. I would appreciate your input on the budget section before the meeting on Friday. Please advise on any changes you recommend.
I look forward to your response.
Best regards,
James

Casual Conversation Example

Friend: “Are you coming to the party on Saturday?”
You: “Not sure yet. Keep me posted on the time.”
Friend: “Sure, I’ll give you a shout later.”

Workplace Speaking Example (Informal)

Colleague: “I’m checking with the client about the deadline.”
You: “Okay, just tell me what they say.”

Common Mistakes to Avoid

Mistake 1: Using “Please advise” in casual conversation

Wrong: “Please advise if you want pizza for dinner.”
Right: “Let me know if you want pizza for dinner.”

Why: “Please advise” sounds too formal for everyday situations. It can make you seem distant or robotic.

Mistake 2: Using “Hit me up” in a professional email

Wrong: “Hit me up when the report is ready.”
Right: “Please let me know when the report is ready.”

Why: “Hit me up” is slang and can be seen as unprofessional. It may confuse non-native speakers or older colleagues.

Mistake 3: Being too vague with “Let me know”

Wrong: “Let me know about the project.”
Right: “Let me know if you need any help with the project.”

Why: “Let me know” without context can be confusing. Always specify what you need to know.

Mistake 4: Overusing “I would appreciate your input”

Wrong: “I would appreciate your input on what time we should meet.”
Right: “Please let me know what time works for you.”

Why: “I would appreciate your input” is best for complex feedback. For simple questions, it sounds exaggerated.

Better Alternatives for Specific Situations

For Asking a Deadline

• Formal: “Please advise on the submission deadline.”
• Casual: “When do you need this by?”

For Requesting Feedback

• Formal: “I would appreciate your feedback on the attached document.”
• Casual: “What do you think of this?”

For Asking About Availability

• Formal: “Kindly inform me of your availability for a meeting next week.”
• Casual: “Are you free sometime next week?”

For Closing a Message

• Formal: “I look forward to your response.”
• Casual: “Talk to you later.”

Mini Practice: Choose the Right Phrase

Read each situation and choose the best alternative. Answers are below.

1. You are writing to your manager about a project update. What is the best phrase?
a) Hit me up when you know.
b) Please advise on the next steps.
c) Just tell me what to do.

2. You are texting a friend about weekend plans. What is the best phrase?
a) Kindly inform me of your plans.
b) Keep me posted on what you decide.
c) I would appreciate your input.

3. You are emailing a client about a proposal. What is the best closing?
a) I look forward to your response.
b) Give me a shout when you read it.
c) Let me know when you can.

4. You are asking a colleague for feedback on a presentation. What is the best phrase?
a) I would appreciate your input on the slides.
b) Hit me up with your thoughts.
c) Just tell me if it is good.

Answers

1. b) Please advise on the next steps. (Formal and respectful to a manager.)
2. b) Keep me posted on what you decide. (Casual and friendly for a friend.)
3. a) I look forward to your response. (Professional and polite for a client.)
4. a) I would appreciate your input on the slides. (Polite and specific for feedback.)

Frequently Asked Questions

1. Can I use “Let me know” in formal emails?

Yes, but add “please” to make it polite: “Please let me know.” It is a safe choice for most professional situations. For very formal contexts, use “Please advise” or “I would appreciate your input.”

2. Is “Keep me posted” too casual for work?

It depends on your workplace culture. In many offices, “Keep me posted” is acceptable with colleagues you work with regularly. Avoid it in emails to senior managers or external clients.

3. What is the most polite way to ask for information?

The most polite way is to use a full sentence that shows respect: “I would appreciate it if you could let me know your thoughts on this matter.” This is very formal and works well in official correspondence.

4. Can I use “Give me a shout” in a professional email?

No. “Give me a shout” is very informal and should only be used in spoken conversation or text messages with close friends. In professional emails, use “Please let me know” or “I look forward to hearing from you.”

Final Tips for Using These Phrases

Always consider your audience and the context. If you are unsure, choose a neutral option like “Please let me know” or “I’d like to hear your thoughts.” These work in most situations without sounding too formal or too casual. Practice using the alternatives in real conversations and emails to build your confidence. For more help with everyday polite phrases, visit our Polite Everyday Phrases section. If you need guidance for workplace communication, check out Workplace Speaking Phrases. For professional email writing, see our Professional Email Alternatives category. You can also learn more about our approach on our About Us page or read our Editorial Policy for how we create our guides.