Word Choice - Outside or Outside of | Ontario Training Network

Hilary’s question: “The question I have is the use of ‘of’ in a phrase such as, ‘If you live outside of Canada, a visa is required.’ Is it correct to say, ‘If you live outside Canada, a visa is required’ “?

BizWritingTip response: This is a style issue. British grammar purists consider “outside of” incorrect. However, in North American English, it is deemed acceptable both in written and in spoken form.

Examples

I waited outside of his building. (North American style)

I waited outside his building. (British style)

The rational for the North American style is that “outside” can be considered either a noun or a preposition. If the word “of” follows, “outside” is definitely a preposition. Apparently, it makes a subtle change in how the reader understands the sentence.

Personally, I prefer the British style: “If you live outside Canada, you need a visa.” But whatever you decide will be fine.