In, On, At (Other Uses)

Why This Matters

You already know that in, on, and at describe places and times. But these three prepositions also appear in dozens of fixed phrases that have nothing to do with location or the clock. Choosing the wrong one sounds strange to native speakers and can cost you points on the TOEIC. The good news: most of these phrases just need to be memorised as chunks.

Phrases with in

Weather and conditions

Use in when you describe the conditions around you.

Phrase	Example
in the rain	The delivery team was working in the rain all morning.
in the sun	Let’s hold the team photo in the sun — the lighting is better.
in the shade	It’s 35 degrees outside. We should eat lunch in the shade.
in the dark	The power went out and we had to finish the meeting in the dark.
in bad weather	Flights are often delayed in bad weather.

Language and currency

When you talk about the language something is written or spoken in, or the currency something is measured in, use in.

• The user manual is in Japanese, but the summary is in English.
• How much is 500 euros in dollars?
• Could you repeat that in simpler terms, please?

Feelings, opinions, and states

Phrase	Example
in love (with)	He fell in love with the city during his first business trip.
in a good/bad mood	The manager is in a bad mood today — the quarterly numbers are down.
in my opinion	*In my opinion, we should delay the product launch by two weeks.*

Phrases with on

Media and communication

Use on when you talk about the device or channel you receive information through.

Phrase	Example
on TV / on television	Did you see the CEO’s interview on TV last night?
on the radio	I heard the traffic report on the radio on my way to the office.
on the phone	Sorry, I can’t talk right now — I’m on the phone with a client.

Other common on phrases

Phrase	Meaning	Example
on fire	burning	The warehouse is on fire — call the emergency services!
on purpose	intentionally, not by accident	He deleted the file on purpose because it contained errors.
on the whole	generally, overall	*On the whole, the project went well despite a few setbacks.*

Travel, absence, and activities: on + noun

Several phrases follow the pattern be/go + on + noun to describe a type of trip or activity.

Phrase	Example
on holiday / on vacation	Half the team is on holiday this week.
on a trip / on a tour / on a cruise	We went on a tour of the new factory in Osaka.
on business	Sarah is in New York on business until Thursday.
on strike	The bus drivers are on strike, so I’ll take the train.
on a diet	I’m on a diet, so no cake for me at the office party.

Note the difference: you go on holiday, but you go to a place for a holiday. We’re going on holiday next month. / We’re going to Spain for a holiday.

Phrases with at

Age, speed, and temperature

Use at when you state a precise number for age, speed, or temperature.

Phrase	Example
at the age of … / at 16	She got her first management role at the age of 28.
at 120 km/h	The train was travelling at 300 kilometres an hour.
at 100 degrees	Water boils at 100 degrees Celsius.

Think of at as pointing to an exact value on a scale.

Summary: Quick Reference

Preposition	Use it for	Key phrases
in	conditions, language, currency, feelings, opinions	in the rain, in French, in love, in my opinion
on	media, fire, purpose, trips, activities	on TV, on the phone, on holiday, on strike
at	precise numbers (age, speed, temperature)	at 25, at 90 mph, at 100°C

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