Outside

Outside is an adverb, an adjective, a preposition or a noun.

We use outside as an adverb or an adjective to mean ‘not in a building’:

• It was sunny outside, but not very warm. (adverb)
• It’s a bit dark at night. We could put an outside light there. (adjective)

Outside can also mean ‘external’, not part of an existing plan or situation:

• They’re calling on outside investors for more support.

We use outside or outside of as a preposition to mean ‘not in a particular place, but near it’:

• There’s a chair just outside the room opposite.
• She works in a software development company just outside of Dublin.

As a preposition, we also use outside or outside of to mean ‘anywhere else apart from a particular place’:

• There is a weight limit of 750g for letters outside Europe.

Outside of can also be used with time expressions to mean ‘excluding’ or ‘apart from’:

• Outside of the summer months, the hotel rates are lower.

Outside as a noun is used to refer to the exterior of something. It is more informal than exterior:

• The outside of the house is not very attractive, but inside it is beautiful. (or, more formal, The exterior of the house …)