Do you use plural with decimal quantifier?

Which of the following is accepted as correct? “0.5 liters of water” or “0.5 liter of water” ?

“0.5 liters” sounds better to me, though I don’t know how I’d justify it except that the 5 in there sounds plural. You could avoid the issue by saying “500 millilitres” or “0.5 l”.

The former. The singular unit is appropriate only when there is exactly 1 unit present.

If you express the fractional portion of a unit as a proper fraction (rather than a decimal), then it functions as a multiplier against a single unit.

So “0.5 liters of water” is the same as “half [of] a liter of water.”

0.5 is less than the unit, so it can’t be plural.

“0.5 liter of water”

That’s not the issue. This isn’t a matter of logic; it’s purely convention.

As a native American English speaker, “0.5 liters of water” sounds a little better to me than without the ‘s’, even though “half a liter” is much much better than with the ‘s’. The alternative of “0.5 liter of water” isn’t a horrible glaring mistake though.

Like guizot said, this is language, not logic.

Don’t attempt to apply logic to English style or grammar. That way lies madness.

The correct answer is as posted above: the singular is only used for exactly one unit.

So 1 liter of water, or 0.5 liters of water.

Now you might say, “but wait! What about fractions? Nobody says three fourths liters water!”

And that’s because when dealing with fractions there is an implicit whole liter there. One says “three fourths of a liter of water.” You can drop the “of” for brevity. Or just say 750mL, which is probably clearer.

nm. Covered at the end of your post.

in my experience in an environment that use the metric system (science), you will often hear the singular because it is.

the decimal ending in a number greater than one gives a tendency for the plural to sound better to many.

You could just say “about one pint” and avoid the problem.

What if you were to say 1.0 liters, i.e. “one point zero liter(s)”, emphasizing the accuracy of the information? Even in that case, I want to include the “s”.

No – you need to specify what kind of “pint” – 473, 551 or 568 ml.

Well, I could say half a liter, but in truth I am looking for a general case, not just pertaining to water. For example, it could also be “The stock index goes up by 0.2 point(s)” or “The goblin suffers 0.43 point(s) of damage”.

I had a conversation about this with my girlfriend on a particularly boring drive some time ago. It was spurred by our Garmin GPS saying “In point-five miles turn left” or some such. I argued the same point: 0.5 is one-half, which is less than one, so it shouldn’t be plural.

My sister’s GPS unit solves the problem completely: It says, using perfect received pronunciation, “After one half of a mile, turn right.” :slight_smile:

–In fact if you are talking about 1.5 liter(s) you still have the problem since you have less than the minimum amount of liters (two) to qualify for pluralness.

I would always say “0.5 liter of water” myself. If it’s not more than 1, then it’s not plural.

I’ve never heard anyone say “point five mile” or something similar. It’s “point five miles” and “point three inches” or whatnot. I’m surprised to hear that people use the singular form for these constructions. It’s not used in the circles of English speakers I talk to.

We obviously talk to different people.

Well, you do live halfway across the world.

Anyways, if you want to be technical, then you wouldn’t be saying “zero-point-five liters” at all. Decimals are read with their place values. So it would be “zero and 5 tenths of a liter.”

Another example would be 0.567 L, which properly should be read “zero and five hundred sixty-seven thousandths liters.”

I think that’s being rather overly pedantic. Stick with what people actually use.

I quote from the Chicago Manual of Style Online FAQ:

in my experience the fractional part of a decimal is not always converted to a fraction to verbalize it.

some applications where fast accurate data transfer is important the characters are read left to right.