Quick answer: Answer is used as a transitive verb followed directly by an object (answer a question / the phone / the door) and is slightly more general. Reply is used for verbal or written responses and is followed by to + object or used intransitively (reply to an email). You cannot say reply the phone. For a fuller definition, see the Cambridge Dictionary entry for ‘answer’.
Comparison Table
| Word | Grammar | Typical contexts | Example |
|---|---|---|---|
| answer | transitive (no preposition needed) | questions, phone, door, email | She answered the question. |
| reply | intransitive or reply to + noun | emails, letters, messages, speech | She replied to the email. |
Using Answer
Answer can be used as a transitive verb, taking a direct object without a preposition. It is versatile and covers physical responses (phone, door) as well as verbal or written responses (questions, emails).
Can you answer the phone?
Please answer my question.
No one answered the door.
I will answer your email later.
Answer as a Noun
Answer is also a common noun meaning a response or solution: the answer to the problem / give an answer / the right answer.
Using Reply
Reply is used mainly for verbal or written responses. As a verb, it does not take a direct object directly — you must use reply to something. It cannot be used with the phone or the door.
She replied to his message immediately.
He replied that he would be late.
Please reply to this email by Friday.
She replied the phone.
Reply as a Noun
Reply as a noun means a spoken or written response: I received no reply / in reply to your letter / wait for a reply.
Common Mistakes
✗ Please reply my email.
✓ Please reply to my email.
✗ Can you reply the door?
✓ Can you answer the door?
✗ Please answer to my question.
✓ Please answer my question. (Note: “answer to” does exist but means “be responsible to”: “She answers to the manager.”)
Also compare: Care vs Mind, Deal With vs Handle, Control vs Manage. Browse all confusing word pairs →
Quick Check: Answer or Reply?
Four questions — choose the correct word.
1. “Can someone ___ the phone?”
2. “Please ___ to my email as soon as possible.”
3. “Nobody came to ___ the door.”
4. “He ___ that he couldn’t attend the meeting.”
Frequently Asked Questions
What is the difference between answer and reply?
Answer is a transitive verb that takes a direct object: answer the phone / answer a question. Reply usually needs “to” before its object (reply to an email) and is used mainly for verbal or written responses, not physical ones like a door or phone.
Can I say “answer to an email”?
No. You answer an email (no preposition) or reply to an email (with “to”). “Answer to” has a different meaning: “She answers to the director” means she is accountable to the director.
Can I use reply for a phone call?
No. For a phone call use answer the phone or return someone’s call. Reply is not used in this context.
Is “reply” used for the door?
No. You answer the door when someone knocks. Reply is only for verbal or written communication.
Can both answer and reply be nouns?
Yes. The answer is the most common noun form for solutions or responses to questions. A reply is a noun for a response to a message or speech: “I received no reply.”
What is the difference between answer and respond?
Respond is more formal and, like reply, takes “to”: respond to a letter. Answer is more everyday and takes a direct object. In meaning, all three overlap but differ in register and grammar.
Which is more formal — answer or reply?
Both are neutral in register. Respond is the most formal. In business writing, reply (“please reply to this email”) and answer (“please answer my question”) are both perfectly appropriate.
Can I say “in answer to” and “in reply to”?
Yes, both are correct and commonly used in formal correspondence: “In answer to your question…” / “In reply to your letter of 5 June…” Both are standard phrases.
Is “answer back” rude?
In British English, “answer back” usually implies rudely contradicting someone: “Don’t answer back!” It is different from simply answering or replying.
How do I use reply in reported speech?
Reply can introduce reported speech directly: “He replied that he would be late.” Answer works the same way: “She answered that she didn’t know.” Both are correct in reported speech.