Quick and quickly both relate to speed, but they usually play different grammar roles. Quick most often describes a noun, while quickly describes an action.
You can say a quick reply, a quick meeting, or a quick decision because each phrase describes a thing. When you describe how someone acts, moves, answers, learns, or finishes something, quickly usually gives you the cleaner choice.
Quick Answer
Use quick when you need an adjective: “That was a quick call.” Use quickly when you need an adverb: “She answered quickly.” In casual speech, quick sometimes works as an informal adverb, as in “Come quick,” but quickly sounds better in formal, school, business, and edited writing.
Why People Confuse Them
People confuse quick and quickly because both words point to speed or short time. Their spelling also looks closely related because quickly adds -ly to quick.
Another source of confusion comes from English itself. Some words work as both adjectives and adverbs. For example, fast can describe a noun or an action: “a fast car” and “drive fast.” Quick has more limits. It mainly works as an adjective, though casual speech sometimes uses it as an adverb.
Sentence position can also mislead writers. A word at the end of a sentence may describe either a noun or an action.
Correct: “Make it quick.”
Correct: “Finish it quickly.”
In the first sentence, quick describes it. In the second sentence, quickly describes finish.
Key Differences At A Glance
| Context | Best Choice | Why |
| Describing a noun | quick | Use an adjective before or after a noun. |
| Describing an action | quickly | Use an adverb to describe how something happens. |
| Formal writing | quickly for actions | It is the standard adverb form. |
| Casual command | quick or quickly | “Quick!” sounds natural in urgent speech. |
| After linking verbs like be, seem, or look | quick | These verbs often connect the subject to an adjective. |
| After action verbs like run, answer, move, or finish | quickly | These verbs usually need an adverb. |
Meaning and Usage Difference
Quick means fast, prompt, brief, or taking little time. It usually describes a person, thing, reply, action, decision, meeting, look, or process.
A quick call means the call will not take long.
When an answer is quick, it comes soon or takes little time.
A quick learner is someone who learns fast.
Quickly means in a quick way, at a fast speed, or after a short time. It describes the action in the sentence.
She answered quickly.
The team moved quickly after the deadline changed.
He quickly realized the address was wrong.
A simple way to remember the difference:
- Quick describes a noun: a quick update, a quick drive, a quick fix.
- Quickly describes a verb: update quickly, drive quickly, fix it quickly.
- Quick can stand alone in urgent speech: “Quick! Grab your coat.”
- Quickly works better when the sentence needs a standard adverb.
Tone, Context, and Formality
Quick sounds natural in everyday English when it works as an adjective. Phrases such as a quick call, quick service, and a quick question do not sound casual or incorrect.
Quickly sounds more polished when it describes an action. It fits school writing, workplace messages, instructions, reports, and edited articles.
Casual speech often uses quick as an adverb:
“Come quick!”
“Let’s leave quick.”
“She got here real quick.”
Those sentences sound natural in conversation, but they sound informal. In careful writing, choose these versions instead:
“Come quickly.”
“Let’s leave quickly.”
“She got here really quickly.”
One-word urgency creates an exception. Quick! works well when you want someone to hurry right away.
Which One Should You Use?
Choose quick when the word describes what something is like.
Use quick with nouns:
a quick email
a quick lunch
a quick decision
a quick look
a quick response
Choose quickly when the word describes how something happens.
Use quickly with action verbs:
respond quickly
move quickly
finish quickly
learn quickly
change quickly
Ask one simple question: What does the word describe?
Use quick when the word describes a person, place, thing, idea, reply, call, or meeting.
Use quickly when the word describes an action.
Quick describes what something is like. Quickly describes how something happens.
When One Choice Sounds Wrong
Quickly sounds wrong when you place it before a noun as if it were an adjective.
Incorrect: “I need a quickly answer.”
Correct: “I need a quick answer.”
Incorrect: “We had a quickly meeting.”
Correct: “We had a quick meeting.”
Quick can sound too casual when it describes an action in formal writing.
Casual: “Please reply quick.”
Better: “Please reply quickly.”
Casual: “The file downloaded quick.”
Better: “The file downloaded quickly.”
The pattern be quick is correct because quick describes the subject.
Use quick after be: Be quick.
After a linking verb, quick describes the subject: The service was quick.
A response or movement can also be quick: Her reaction was quick.
Do not replace quick with quickly in those sentences.
Incorrect: “Be quickly.”
Incorrect: “The service was quickly.”
Common Mistakes (and Quick Fixes)
Mistake: “Send me a quickly reply.”
Fix: “Send me a quick reply.”
Why: Reply is a noun, so it needs the adjective quick.
Mistake: “She finished the form quick.”
Fix: “She finished the form quickly.”
Why: The word describes how she finished.
Mistake: “The meeting was quickly.”
Fix: “The meeting was quick.”
Why: Was links the subject to an adjective.
Mistake: “He is a quickly learner.”
Fix: “He is a quick learner.”
Why: Learner is a noun, so use quick.
Mistake: “Move quick in the hallway.”
Fix: “Move quickly in the hallway.”
Why: Move is an action verb, so quickly sounds cleaner.
Mistake: “That was quickly.”
Fix: “That was quick.”
Why: Quick describes that.
Everyday Examples
Use quick before a noun: I have a quick question before the meeting starts.
Choose quickly when describing an action: Please answer quickly so we can finish the form today.
A short task can be described as quick: That was a quick grocery run.
When the action matters, use quickly: The nurse quickly checked the patient’s chart.
Before a noun like decision, quick works naturally: We need a quick decision by noon.
For how something happened, quickly is the better choice: The app loaded quickly after the update.
A brief expression can be quick: She gave a quick smile and walked into class.
To describe fast noticing, use quickly: He quickly noticed the typo in the subject line.
Before break, choose quick: Can we take a quick break?
When describing fast reaction, use quickly: The driver reacted quickly when the light changed.
Casual: “Come quick!”
More polished: “Come quickly!”
Casual: “I’ll do it real quick.”
More polished: “I’ll do it really quickly.”
Dictionary-Style Word Details
Verb
Quick: Quick does not commonly work as a verb in standard modern US English. Use quicken when you mean “make faster” or “become faster.”
Quickly: Quickly does not work as a verb. It works as an adverb.
Noun
Quick: Quick can work as a noun in limited expressions. In the quick, it can refer to sensitive flesh under a nail or a deeply sensitive emotional place, as in “cut to the quick.”
Quickly: Quickly does not work as a noun in standard US English.
Synonyms
Quick: Closest plain alternatives include fast, brief, prompt, swift, rapid, and speedy. The best choice depends on the noun. A quick call is usually a brief call. A quick response is usually a prompt response.
Quickly: Closest plain alternatives include fast, rapidly, speedily, promptly, swiftly, and soon. Use slow as a common opposite of quick and slowly as the clear opposite of quickly.
Example Sentences
Quick:
“She took a quick shower before work.”
“We need a quick answer from the manager.”
“That was a quick fix, but it worked.”
Quickly:
“She quickly packed her bag.”
“The team responded quickly to the client’s request.”
“The room filled quickly after the doors opened.”
Word History
Quick: Quick has older meanings connected to being alive or sensitive. That history helps explain phrases like the quick. In modern everyday use, quick usually refers to speed, promptness, or short time.
Quickly: Quickly comes from quick plus the adverb ending -ly. That ending helps the word describe how an action happens.
Phrases Containing
Quick:
a quick question
a quick answer
a quick look
quick thinking
quick service
make it quick
quick as a flash
cut to the quick
Quickly:
answer quickly
move quickly
finish quickly
as quickly as possible
quickly realized
quickly changed
quickly became clear
act quickly
FAQ
Is it quick or quickly?
Both are correct, but they fit different grammar jobs. Use quick when you describe a noun, as in “a quick answer.” Use quickly when you describe an action, as in “She answered quickly.” For polished writing, quickly is usually better after action verbs.
Can quick be an adverb?
Quick can work like an adverb in casual speech, especially in short commands such as “Come quick!” or informal phrases like “real quick.” However, this use sounds conversational. In school, business, and formal writing, quickly usually sounds more correct.
Is “very quick” correct?
Yes. Very quick is correct because very modifies the adjective quick. You can say “That was a very quick meeting” or “She made a very quick decision.” Do not use “very quickly” before a noun.
Is “very quickly” correct?
Yes. Very quickly is correct when it describes an action. For example, “He finished very quickly” sounds natural. In that sentence, very strengthens quickly, and quickly describes how he finished.
Should I say “reply quick” or “reply quickly”?
Use reply quickly in careful writing. “Reply quick” can sound casual, and people use it in relaxed speech. Still, “Please reply quickly” sounds clearer and more professional in emails, schoolwork, and workplace messages.
Is “real quick” wrong?
“Real quick” is common in casual US speech, as in “Let me check real quick.” In polished writing, use really quickly or rewrite the sentence. For example, “Let me check quickly” sounds cleaner and more formal.
Conclusion
Quick and quickly are both correct, but they usually belong in different places. Use quick to describe nouns: a quick reply, a quick call, a quick decision. Use quickly to describe actions: reply quickly, move quickly, decide quickly.
For clear US English, keep the rule simple: quick describes things; quickly describes actions. Casual speech may use quick as an adverb, but quickly remains the safer choice when your writing needs to sound correct, clear, and professional.
Both are correct, but they fit different grammar jobs. Use quick when you describe a noun, as in “a quick answer.” Use quickly when you describe an action, as in “She answered quickly.” For polished writing, quickly is usually better after action verbs.
Quick can work like an adverb in casual speech, especially in short commands such as “Come quick!” or informal phrases like “real quick.” However, this use sounds conversational. In school, business, and formal writing, quickly usually sounds more correct.
Yes. Very quick is correct because very modifies the adjective quick. You can say “That was a very quick meeting” or “She made a very quick decision.” Do not use “very quickly” before a noun.
Yes. Very quickly is correct when it describes an action. For example, “He finished very quickly” sounds natural. In that sentence, very strengthens quickly, and quickly describes how he finished.
Use reply quickly in careful writing. “Reply quick” can sound casual, and people use it in relaxed speech. Still, “Please reply quickly” sounds clearer and more professional in emails, schoolwork, and workplace messages.
“Real quick” is common in casual US speech, as in “Let me check real quick.” In polished writing, use really quickly or rewrite the sentence. For example, “Let me check quickly” sounds cleaner and more formal.
