What does ‘and/or’ really mean?

Lesley Hanes | August 10, 2016

Writing ‘and/or’ in a sentence seems like an economical way to cover a couple of alternatives at once, doesn’t it? That’s what I thought before I started working with words for a living.

I’ve since discovered that little old ‘and/or’ can mean several different things. Take this sentence, for example:

‘I’m going skydiving and I plan to stay calm using positive affirmations and/or deep breathing.’

That could mean I plan to stay calm:

1. using positive affirmations and deep breathing
2. using positive affirmations or deep breathing
3. using positive affirmations or deep breathing or both.

If I’m going to use both methods, number 1 is correct. If I’m going to choose one method or the other, number 2 is accurate. If I might use both methods or just one, number 3 is the right choice.

Whichever combination I choose, I need to get rid of ‘and/or’ altogether to be clear and accurate.

My approach to skydiving only affects me, but what if ‘and/or’ appears in a policy document or a legal contract? How would readers know which of the possible meanings was the correct one? Short answer — they wouldn’t know for sure, and that could cause problems.

In The Redbook: A Manual on Legal Style, author Bryan Garner describes ‘and/or’ as ‘especially unfit for legal writing because it is inherently ambiguous’.

So if you find yourself tempted to write ‘and/or’, take a step back and think through what you really mean.

And if you’re planning to stay calm while skydiving, the very best of luck to you!