In My Spare Time or On My Spare Time? The Correct Phrase and How to Use It Naturally

Language confuses us enough without time phrases acting up too. One of the most persistent questions learners and writers keep asking is: should I say in my spare time or on my spare time? You might have heard both. One sounds right. The other doesn’t. Yet many hesitate because spoken English is full of exceptions.

This guide drops the guesswork. You’ll learn not just the answer but why it’s correct. You’ll get examples, lists, tables, memory tricks, and common pitfalls. By the end, you’ll feel confident using this phrase in any conversation or writing.

Imagine you’re chatting with a friend about hobbies. You want to say you read novels, work out, learn guitar, or build apps when you’re free. You might start with “on my spare time,” but that sounds off to native speakers. Even many advanced learners trip here.

Table of Contents

The Short Answer

✅ Correct: in my spare time
❌ Incorrect: on my spare time

Why? English uses in to talk about chunks of time — like months, years, and free periods. On fits days, dates, and surfaces. Spare time is a period, not a surface or specific date, so in fits perfectly.

Example:
I practice Spanish in my spare time.

That’s natural. It feels right. Let’s dig into why.

Why “In My Spare Time” Is Correct

“At its core, English prepositions show relationships — in this case, between time and activity.”

Spare time refers to the block of free time you have after work, school, or duties. Prepositions handle time differently depending on the scale:

Preposition	Used For	Examples
in	Periods of time	in my spare time, in the morning, in July
on	Specific days/dates	on Monday, on July 4th
at	Specific times	at noon, at 7 PM

Look at the pattern above. We use in with broader time chunks.

Spare time works like this:

It’s not a day or date
It’s not a clock time
It’s a span of time we fit things into

That matches with in.

Why “On My Spare Time” Sounds Wrong

You might wonder why it feels off to many learners. The error happens because people learn on with time and mix patterns.

Let’s clear it up:

On is for:
- Days (on Monday)
- Dates (on August 12th)
- Surfaces (on the table)
In is for:
- Periods (in my free time)
- Seasons (in summer)

Because spare time isn’t a day, date, or surface, you don’t use “on”.

Saying on my spare time is like saying on my summer — it doesn’t fit the grammar pattern native speakers learned instinctively.

In My Spare Time — Real-Life Examples (With Context)

Below, you’ll find sentences you can use right away. Each shows real English usage.

Common Daily Uses

I learn graphic design in my spare time.
She plays tennis in her spare time after work.
We watch documentaries in our spare time.
They volunteer in their spare time on weekends.

Professional Growth

I study marketing in my spare time to boost my career.
He builds websites in his spare time and sells them online.
She writes blog posts in her spare time to grow her audience.

Creative and Hobby Examples

I paint landscapes in my spare time.
He courts scenes for his novel in his spare time.
They learn calligraphy in their spare time for fun.

Each example shows in as the correct choice. No native speaker would say on my spare time in everyday talk.

Common Mistakes Learners Make

Let’s bust some time-related preposition errors that often show up with spare time.

Wrong Phrase	Why It’s Incorrect	Correct Version
on my spare time	Uses on incorrectly with abstract time	in my spare time
at my spare time	At is for specific points in time	in my spare time
during my spare times	Spare times isn’t standard; uncountable	in my spare time
on spare time	Same issue with on	in spare time

Notice how adding or subtracting tiny words changes the meaning or grammar. English depends on patterns, so recognize them early.

“Spare Time” vs “Free Time” — A Quick Comparison

You might hear in my free time and wonder if it’s the same as in my spare time.

Phrase	Meaning	Common Usage
in my free time	Time without obligations	Very common across levels
in my spare time	Extra pockets of time after duties	Slightly more casual

Both are correct and mean almost the same thing. The difference is tiny, like saying movie vs film. Both fit, just different flavors.

Examples:

I practice piano in my free time.
I sketch characters in my spare time.

Both work beautifully.

Similar English Time Expressions With “In”

See how the preposition in ties a time phrase to an activity:

in my free time
in my spare time
in my downtime
in my off time
in the early morning
in the afternoon

Notice: They all refer to spans, not moments on a clock or specific days.

Memory Trick to Never Forget

Here’s a simple way to lock it into your brain.

Picture This

Imagine time like a room.

You go into that room to do things.
You do tasks inside that block.
You are in time, not on time.

So it clicks:

I do X in my spare time because I am inside that little block of time.

Here’s a visual memory clue:

┌───────────── Spare Time ──────────────┐

| |

| I read comics in my spare time. |

| I practice coding in my spare time. |

└───────────────────────────────────────┘

Visualize it as a container you step into to do activities.

Is “On My Spare Time” Ever Correct?

Short answer: No, not in standard English.

Native speakers and most dictionaries don’t accept on my spare time as correct. It’s not a recognized pattern in formal grammar.

Some speakers might say it due to:

Influence from native language patterns
Direct translation
Informal speech in a group

But that doesn’t make it standard.

If you care about clear, natural English, skip “on my spare time.” Always choose in.

How Native Speakers Actually Say It

Native usage patterns reveal what sounds natural.

Here are real phrases you’ll hear:

“I paint in my spare time.”
“In my spare time, I love to garden.”
“She writes poetry in her spare time.”
“He builds robots in his spare time.”

Notice how consistently in appears with free time activities.

Practice Section (Quick Quiz)

Fill in the blanks with in or on:

I learn guitar ___ my spare time.
She reads novels ___ her free time.
We catch up with friends ___ the weekend.
He watches movies ___ his spare time.

Answers:

Case Study: Why Prepositions Matter in English Fluency

A learner named Anna struggled to speak fluently because she mixed time prepositions. She often said:

I learn French on my free time

That sounded odd to native listeners.

After understanding patterns like in for time periods and on for days/dates, she switched to:

“I learn French in my spare time.”

The change made her speech sound instantly more natural. Listeners understood her faster, and she felt more confident.

This shows how small words shape clarity.

Final Rule to Remember

Here’s the simple rule:

🔹 Use IN for time periods like spare time
🔹 Use ON for days and dates
🔹 Use AT for exact times

So always say:

in my spare time

Not:

on my spare time

FAQs

Is “on my spare time” ever acceptable in casual speech?

Not in standard English. You might hear it from learners or in direct translations from other languages, yet native speakers don’t use it naturally. If you want fluent, natural English, stick with in my spare time every time.

Why do we use “in” with spare time instead of “on”?

Because spare time is a time period, not a day or surface. English uses in for longer or general time blocks like in the morning, in summer, and in my free time. The pattern stays consistent.

Can I say “during my spare time” instead?

Yes, you can. It’s grammatically correct, though slightly more formal. In daily conversation, in my spare time sounds smoother and more natural.

Example:
I study photography during my spare time.
I study photography in my spare time.
Both work, the second sounds more relaxed.

Is “spare time” the same as “free time”?

Almost. They overlap a lot.

Phrase	Meaning	Tone
Spare time	Extra time after responsibilities	Slightly casual
Free time	Time without duties or work	Very common and neutral

Both use in, not on.

Where should I place “in my spare time” in a sentence?

You have flexibility. It can go at the start or end.

Start: In my spare time, I build mobile apps.
End: I build mobile apps in my spare time.

Conclusion

Tiny words carry big weight in English. One small preposition can decide whether your sentence sounds fluent or awkward. The correct phrase is always in my spare time because it describes a period you step into, not a day you land on.

Lock that rule in your mind and you’ll avoid dozens of common mistakes beyond this phrase. Now you can talk about your hobbies, skills, and passions with confidence and clarity — all happening in your spare time.