in

1

I took a taxi in the airport.
I took a taxi at the airport.

Use at when referring to an airport as a general location: ‘The taxi was waiting at the airport.’

Use in when you specifically mean inside the airport building: ‘There are several shops in the airport.’

Check our grammar lesson on at, in and on as prepositions of place.

2

I saw her in the party.
I saw her at the party.

Use at with parties, celebrations and other social events: ‘We met them at a party last night.’

3

I went in the office, but the manager wasn’t there.
I went into the office, but the manager wasn’t there.

Use in to talk about the position of someone or something: ‘The manager was in the office.’

Use into for movement from outside to inside: ‘I went into the office.’ ‘He came into my room without knocking.’