Practise or practice?

I have a friend, currently working in South Korea, who writes books on speech patterns and accents. She and her editor asked me to help resolve their problems with the difference between practice and practise. The same problems arise with licence and license, and we can’t even blame Bill Gates’s spelling checker for the difficulty; both forms are “legal” in the major varieties of English.

My friend gave me a number of examples, and asked me to comment on them.

Here’s how I replied:

This is a bit fraught, because (a) it’s a US v The Rest of The World thing, and (b) the Americans aren’t consistent about it.

In the UK and Australia, the “rule” is practice as a noun and practise as a verb (think of “ICE is a noun” and “this IS a verb”). In the US, one “rule” is precisely the reverse of that, and the other (more prevalent, I think) is to use practise regardless. So you really have to decide who—or rather where—your audience is.

To your examples:

A sound practice.: OK in the UK and Australia; wrong in the US.

He is practiced.: Wrong here; OK to some Americans.

I practise every day.: OK here; OK to most Americans.

Your practise session. (Or, does this act rather like two nouns, which would make it “practice session”?): Indeed, it’s two nouns—although the first noun is being used as an adjective. So “practice session” is OK here and for some Americans; “practise session” is wrong here but right for most Americans.

Keep practising.: OK here; OK to most Americans. (Present participle of verb.)

A practised hand.: OK here; OK to most Americans. (Past participle of verb.)

Take me out of my misery if you can.: Hah! Next thing, you’ll be asking for the rules of English to be rational and consistent! Fat chance!
(Sorry if this is a bit inconclusive; that’s the way things are, I’m afraid!)

To repeat: it’s all a matter of who—or where—your audience is. Most of us, I imagine, write for a local audience; the “ICE is a noun, this IS a verb” principle works. However, often it isn’t so easy. I’ve just finished a project for an Australian company that sells its software throughout the world, and fortunately company style is specific about always using US English. (Not that the choice itself is fortunate, but at least they’ve made one!) What if your client or employer hasn’t made a decision?

There’s no denying that many readers in Australia and the UK are annoyed by US spellings and other language habits. Similarly, those US readers who are aware of the world outside their own borders probably think the rest of us have strange ideas. In both cases, at least there’s little risk of misunderstanding. But there is a risk that our readers will think we’ve got it wrong; the only way to avoid that risk is to be rigorously consistent in the model you follow. Whichever variety of English you use, stick with it in every respect. Pick one dictionary and one style guide—for Australian English, the Macquarie Dictionary and the AGPS Style Manual; for US English, the American Heritage (or, at a pinch, Webster’s) Dictionary and the Chicago Manual of Style. And, when in doubt, refer to those books, to ensure that you make the right choice.