Of in expressions of measurement and quantity

[ademoglu]

Hi,

I am a little bit confused about whether or not I should put 'of' in expressions of measurement and quantity.

In Michael Swan's book ''Practical English Usage'' (p. 226), it is said that ''Of is not used in expressions of measurement and quantity.''

However, in the book ''The American Heritage Guide to Contemporary Usage and Style'' (p. 213), it is said that ''The phrases a half, half of, and half a or half an are all correct, though they may differ slightly in meaning. For example, a half day is used when day has the special sense "a working day," and the phrase then means "four hours." Half of a day and half a day are not restricted in this way and can mean either four or twelve hours.''

Could you please help me with that?

Thanks.

 

[SoothingDave]

Can you give an example of what you are asking about?

 

[ademoglu]

Sorry for not giving you examples regarding it.

Half of a mile.
Half of an hour.

Now, should I omit 'of'?

 

[Matthew Wai]

I would omit it.

 

[SoothingDave]

You're really asking about "half," not about measurements in general.

While we'll say "half a mile" or "a half mile," we would say "three-eights of a mile" or "four quarts of motor oil."

 

[emsr2d2]

"Half" is the only example I can think of where we omit it.

An eighth of a mile.
A quarter of a mile.
Half a mile.
Two-thirds of a mile.
Three-quarters of a mile.

 

[SoothingDave]

I'd probably say "a quarter mile" or maybe "three-quarter mile" if speaking colloquially. "It's about a quarter mile up the road."

 

[emsr2d2]

That is a BrE vs AmE difference I was already aware of. It's similar to the fact that in BrE, we always say "a couple of ..." and my AmE-speaking friends tend to say "a couple ...".