OK: you know it’s “a” with a consonant and “an” with a vowel. But what about something written with digits?
Simple, actually, and no different from the rule with written words: it goes with the spoken sound (and not necessarily the first letter, as was discussed in a previous post). So it’s:
- an 18th-century drawing room
- an 11th-hour deal (for those with Brexit on their minds)
- an XI without a recognized wicket-keeper
- a 1-week holiday
- a 0.7% fall (if you say “nought” or “zero”) or an 0.7% fall (if you say “oh”)
- an 007 movie (if you say “oh-oh”) or a 007 movie (if you say “double-O”)
In those last two cases, it even gives you a hint of what was in the author’s mind at the time!
Prevalence: low. But it did generate a brief discussion on one of the user groups I follow, so it’s worth including.
Frequency: low. Not an issue I can actually recall seeing in an editing job.
Native: no. We’re used to speaking the language, and we just write what we’d say.