Quick Answer
The correct phrase is “in my spare time.”
The phrase “on my spare time” is incorrect in standard English.
👉 Use “in my spare time” when talking about activities you do during free periods.
Examples:
- I read books in my spare time. ✅
- I read books on my spare time. ❌
👉 Simple rule: Use “in” for general time periods, not “on.”
In My Spare Time vs On My Spare Time
| Phrase | Correct? | Meaning | Usage | Example |
| In my spare time | ✅ Correct | Refers to free time | Used in all contexts | I exercise in my spare time |
| On my spare time | ❌ Incorrect | Grammatically wrong | Not used by native speakers | ❌ I exercise on my spare time |
👉 This table alone answers the query clearly, which helps target Google featured snippets.
Why “In My Spare Time” Is Correct
To truly understand this, we need to go beyond rules and look at how English conceptualizes time.
Time as a “Container”
In English, time is often imagined as a container.
Think of it like this:
- You are inside a period of time
- That’s why we use “in”
👉 Examples:
- In the morning
- In 2025
- In my spare time
So when you say:
“In my spare time”
You’re literally saying:
👉 Inside that free time period
How “In” Works with General Time Periods
The preposition “in” is used for:
- Long periods → in the year
- General time → in the morning
- Non-specific time → in my free time
“Spare time” is not a specific moment.
It’s a general, flexible period.
👉 That’s why “in” fits perfectly.
Why “Spare Time” Fits This Rule
“Spare time” is:
- Not fixed
- Not scheduled
- Not tied to a specific day
It’s a broad, undefined time block.
So naturally:
✔ We use “in”
❌ Not “on”
Why “On My Spare Time” Is Incorrect
Now let’s break down why this phrase sounds wrong to native speakers.
How “On” Is Used with Specific Days/Surfaces
The preposition “on” is used for:
- Specific days → on Monday
- Dates → on July 4th
- Surfaces → on the table
👉 “On” implies something specific or fixed
Why It Doesn’t Work with “Spare Time”
“Spare time” is:
- Not a day
- Not a date
- Not a surface
So using “on” creates a mismatch.
👉 That’s why:
- “On Monday” ✔
- “On my spare time” ❌
Common Learner Mistakes
Many learners say “on my spare time” because:
- Their native language uses a different structure
- They translate directly into English
For example:
- Some languages use one preposition for all time expressions
👉 This leads to confusion.
But in English:
👉 Prepositions are very specific
Native Speaker Usage
If you want to sound natural, it’s important to understand how native speakers actually talk.
How Native Speakers Actually Say It
Native speakers always say:
✔ “In my spare time”
You’ll hear it in:
- Conversations
- Interviews
- Movies
- Professional settings
👉 You will almost never hear “on my spare time”
Frequency & Natural Usage Patterns
“In my spare time” is extremely common in:
- Casual speech
- Job interviews
- Personal introductions
👉 It’s part of everyday English.
Real Sentence Examples from Daily Life
- I like painting in my spare time.
- In my spare time, I go hiking.
- She learns new skills in her spare time.
👉 Notice how natural and fluid these sound.
In My Spare Time in Different Contexts
This phrase is flexible and works across many situations.
Everyday Conversations
In casual speech, it’s very common.
Examples:
- What do you do in your spare time?
- In my spare time, I watch Netflix.
👉 It helps express hobbies and interests.
Professional & Workplace Usage
You’ll often hear it in:
- Interviews
- Networking conversations
Examples:
- In my spare time, I improve my coding skills.
- I volunteer in my spare time.
👉 It shows personality beyond work.
Academic & Formal Writing
Even in formal contexts, it’s acceptable.
Examples:
- The student conducts research in his spare time.
- She studies additional subjects in her spare time.
Interview & Resume Examples
This is where it becomes powerful.
Example answers:
- In my spare time, I build personal projects.
- I read industry-related books in my spare time.
👉 It helps employers understand your mindset.
Similar Phrases and Common Confusions
This is where most articles fail — but this section gives you an edge.
In My Spare Time vs In My Free Time
Both are correct, but slightly different.
- Spare time → unused time
- Free time → available time
👉 In most cases, they are interchangeable.
Examples:
- I exercise in my spare time
- I exercise in my free time
In My Spare Time vs During My Spare Time
Both are correct, but:
- “In” → more natural
- “During” → more formal
👉 Use “in” in everyday conversation.
In My Spare Time vs On My Own Time
This is VERY important.
- In my spare time → free time generally
- On my own time → not during work hours
Example:
- I study in my spare time
- I work on this project on my own time
👉 They are NOT the same.
In My Spare Time vs At My Spare Time
❌ “At my spare time” is incorrect
“At” is used for:
- Specific points → at 5 PM
“Spare time” is not a point — it’s a period.
👉 So:
✔ In my spare time
❌ At my spare time
Common Mistakes to Avoid
Here are the most frequent errors learners make.
- ❌ On my spare time
- ❌ At my spare time
- ❌ In spare time (missing “my”)
- ❌ Spare times (incorrect plural)
👉 Always use:
✔ In my spare time
Practical Examples
Correct Sentence Examples
- I learn new languages in my spare time.
- In my spare time, I enjoy cooking.
- He plays guitar in his spare time.
Incorrect Sentences + Corrections
- ❌ I read books on my spare time
✔ I read books in my spare time - ❌ She studies at her spare time
✔ She studies in her spare time
Dialogue Examples
A: What do you do in your spare time?
B: I usually play football and read books.
👉 This is how real conversations sound.
Also Read: Thank You Very Much vs Thank You So Much: What’s the Real Difference?