Using 'a' or 'an' with quantities

Question

I seem to have trouble deciding whether or not to use 'a' or 'an' when followed by quantities:

Built (a/an) 120 lb. robot.

and

Built (a/an) 18"x 18"x 18" robot.

In terms of pronunciation, the first case could go like:

Built a one-hundred-and-twenty pound robot.

or, like:

Built an a-hundred-and-twenty pound robot.

Which would it be?

… which is discussed (but not entirely resolved) in How to pronounce number, say 1024, in programming world?, How to pronounce 100ish?, 911: nine one one vs. nine eleven, and Why numbers are sometimes pronounced as individual numbers? — Scott - Слава Україні, Jun 07 '16 at 03:26

Caesar · Answer 1 · 2016-06-07T13:20:48.737

1

As usual with the indefinite articles a and an, it depends on the pronunciation of the next word.

I would read your example as: "a hundred-and-twenty pound robot", but "a one-hundred-and-twenty pound robot" would be equally valid.

On the other hand "an a hundred-and-twenty pound robot" would be just wrong. You can't have "an a" together like that.

In your second example, because "eighteen" starts with a vowel sound, it would be "an eighteen-inch by eighteen-inch by eighteen-inch robot".

edited Jun 07 '16 at 13:20

answered Jun 07 '16 at 03:50

Caesar

So what would you use with "eight hundred and twenty-seven"? – Hot Licks Jun 07 '16 at 12:02
@HotLicks you're absolutely right; as the only number which starts with a vowel, eight would need an. I've updated my answer accordingly. – Caesar Jun 07 '16 at 13:11
"Eight" starts with a vowel sound. – Hot Licks Jun 07 '16 at 13:12
'eleven' also starts with a vowel sound. – DJClayworth Jun 07 '16 at 13:27
@Caesar Also "11" - an eleven-inch gap. – TrevorD Jun 07 '16 at 13:28
You are indeed right about eleven. I think that's covered by my answer because I have said that if a number starts with a vowel sound it will need an – Caesar Jun 07 '16 at 14:37

1 Answers1