# "half of pound" or "half of a pound" or "half pound"

Which of the following are the correct sentences:

• you need half of the pound of potatoes.
• you need the half of pound of potatoes.
• you need the half pound of potatoes.
• you need half pound potatoes.
• you need half of a pound potatoes.
• you need half of pound of potatoes.
• you need a half of pound of potatoes.
• you need a half of a pound potatoes.
• you need half a pound of potatoes.
• ...

Is it the same for one third or other fractions of the form 1/x? Does it matter whether I put of in front of potatoes or a in front of half anyway? Do the same rules apply for year or liter instead of pound?

• I didn't realize that I kind of mix two English styles (AmE and the SI system) while writing the question. I asked on meta, if this is bad: english.meta.stackexchange.com/questions/11473/… Jun 8, 2018 at 16:17
• Changed kilogram to pound (edited the answers too) Jun 8, 2018 at 17:47

You need {proportion} of {quantity}{units} of {item}.

That is, a sentence in this format will always be grammatically correct. For example:

You need (one/a) quarter of (one/a) liter of water.

Note that when speaking about a single unit, it's common to replace one with a. For example:

You need a quarter of a liter of water.

It's worth mentioning that in some cultures, such as British English - it would also be appropriate to drop the "a" in "a quarter". But as this only applies to some proportions (quarter/half) I'd recommend an English Language Learner avoids these cases unless very comfortable with local idioms.

However, (in some/most cultures) when talking about halves - this is a special case where you can omit the of. This is simply due to common phrasing, there is no solid rule that makes this possible.

For halves, you can for example write:

You need half a liter of water.

Note that when using half without of, you will always use half a {unit} and never half one {unit}.

For completeness, it should be noted that in some cultures - there are the additional terms "quarter-{unit}" and "half-{unit}", which are short for "quarter of a {unit}" and "half of a {unit}". They would be used as "Put in a half-pint of beer" or "You need a quarter-pound of meat". Again, I'd recommend an ELL not to worry about these usages, as they can differ from region to region - but be aware of them in the case they are found in literature.

you need half of the pound of potatoes.

In this case, the addition of the refers to half of a previously mentioned or specified quantity of potatoes. For example, if you're talking about a recipe that requires you to peel all the potatoes - the next step may talk about using "half of the pound of potatoes" to ensure you use those previously peeled, and not just any potatoes.

Commonly though, you will find this usage split into two parts:

• Firstly, the entire quantity of the item is specified. "Take 1 pound of potatoes and peel them.".

• Then later, the proportion for that specific step is used - without re-iterating the original total quantity. "Fry half of the peeled potatoes." (referring to half of the original kilogram of now peeled potatoes).

To give some additional clarity, here are some example sentences following the above rules:

You need half of a kilogram of potatoes.

You need half a kilogram of potatoes.

You need half of the kilogram of potatoes.

You need a half-kilogram of potatoes.

You need two thirds of a tonne of lead.

You need half a kilogram of flour.

You need a third of a year to complete this.

You need a quarter of a pound of meat.

You need 19/27ths of a gallon of soup.

Notes on non-standard parenthesis uses in this answer:

(A/B) is a non-optional term, but can be either A or B. e.g. "(he/she) rode the bike" must include either he or she.*

{variable} is a term to replace with anything from that category. e.g. "{proportion} of a pound" may be "quarter of a pound" etc.

• Let's continue the "you need quarter" vs "you need a quarter" discussion here: chat.stackexchange.com/rooms/78584/… Jun 7, 2018 at 14:34
• As a native English speaker, I'd like to add that it's perfectly idiomatic (in my dialect of American English) to say "You need a quarter liter of water", though it's more common in weight/mass measurements such as "a quarter pound of beef" (commonly seen in reference to hamburgers, where a quarter pound is the usual weight of one hamburger patty) Jun 7, 2018 at 16:05
• @Felthry That's completely fine in my dialect of British English, too. Jun 7, 2018 at 23:54
• "You need quarter of ..." sounds incorrect to me, and I'm sure I never saw it. (I may have heard it, but I always assumed the "a" was swallowed rather than dropped.) Jun 8, 2018 at 6:16

It is usually wrong to say

you need half of the kilo of potatoes

But I can write a recipe that would need that construction:

Potato Pie

1. one kilo of potatoes plus one small potato
2. 400 grams of flour
3. 500 ml water

• Parboil the potatoes in the water
• Mash half of the kilo of potatoes
• Mix the mashed potatoes with the flour
• Slice the other half of the potatoes
• ...
• Cut the last potato in wedges and decorate the pie

In this case you are referring back to not just a certain weight of potatoes in general, but a specific instance of potatoes that you already have in your context.

This is a much less common usage but not incorrect.

(Note: recipe made up as an example. This kind of divided usage is much more common with flour, sugar, and other culinary building blocks.)

• No need to use a new answer to criticise others - add a helpful comment to shape theirs. Jun 7, 2018 at 11:59
• I was not trying to criticize the other answers, I was providing an example of a usage that is usually wrong (as the other answers indicated) but is occasionally correct in one specific context. I'll edit my answer to make that more clear.
– arp
Jun 7, 2018 at 12:01
• +1 because this is the only answer so far that doesn't seem to promote non-idiomatic versions. @arp - you're perfectly correct that half of the kilo of potatoes is syntactically valid, but is only idiomatically credible in a few "unusual" contexts such as the one you've set out above. I don't know why people are downvoting this answer whilst upvoting others that are manifestly incorrect. Jun 7, 2018 at 13:38
• Ah yet another case of the general form of "is it X or Y" when both X and Y are valid and mean different things. Jun 7, 2018 at 22:34

Which of the following are the correct sentences:

you need half of the pound of potatoes*.
you need the half of pound of potatoes.
you need the half pound of potatoes*.
you need half pound potatoes.
you need half of a pound potatoes.
you need half of pound of potatoes.
you need a half of pound of potatoes.
you need a half of a pound potatoes.
you need half a pound of potatoes.

Basically "half-pound", "half a pound", "half a kilogram" or even "half a kilo" are used so frequently that you could say they have become names of weights in their own right. This is why you may see them used in different ways.

Technically speaking the correct way to say it would be:

Half a pound of potatoes

But as many accept that "half pound" is the name for the weight (8 ounces; 227 grams) it can be expressed:

A half-pound of potatoes.

There are other similar instances where this has become the case - for example "I went on a half-mile run". But it is not the case for all fractions. You would not hear "a third-kilo" used to name a measure, partly because it is confusing - if you said "add a third kilo to the mix" in a recipe it sounds like you have already added two kilos!

• Finally just to add that although I have accepted your two possible sentences where you refer to "the half pound of potatoes", you would only use the definite article if you were referring to a specific half-pound; for example if in your recipe there were two different measures of potatoes used at different points you would say "the half-pound of potatoes" to differentiate from the other measure. If on the other hand there were two equal half-kilo measures of potatoes in the recipe you may well see a recipe specify "one of the half-kilos of potatoes".
• How about one third? Correct are only the sentences one-third kilogram of potatoes and one third a kilogram of potatoes? Jun 7, 2018 at 9:40
• First one - "the half" - I don't like at all; unless you need a specific half... "the first half goes in the pie, the second half in the soup'... Jun 7, 2018 at 9:50
• @Tetsujin agreed, I don't like it either - however this is in the context of a recipe, and some recipes begin by asking you to divide ingredients. For example one half of the sugar may go into the mix, the other half sprinkled on top. If you were referring to a specific half-kilo then you may use "the". It may also be used if a recipe contains two different measures of the same ingredient, and for that reason I haven't scored it out as grammatically incorrect. Jun 7, 2018 at 11:05
• @FumbleFingers "For this recipe you will need one kilogram of potatoes, plus one additional large potato. Take half of the kilogram of potatoes and put them onto boil. Put the other half-kilogram in the oven to bake. Meanwhile, chip the remaining large potato". Jun 7, 2018 at 13:46
• @Kevin It's missing another "of". What is "a kilogram potatoes"? Jun 7, 2018 at 14:48

Which of the following are the correct sentences:

you need half of the pound of potatoes*.
you need the half of pound of potatoes.
you need the half pound of potatoes*.
you need half pound potatoes.
you need half of a pound potatoes.
you need half of pound of potatoes.
you need a half of pound of potatoes.
you need a half of a pound potatoes.
you need half a pound of potatoes.

### Normal case

You need {proportion} of {quantity}{units} of {item}.

That is, a sentence in this format will always be grammatically correct. For example:

You need (one/a) quarter of (one/a) liter of water.

Note that when speaking about a single unit, it's common to replace one with a.

Examples:

You need a quarter of a liter of water.

You need a third of a year to complete this.

You need a half of a pound of meat.

You need 19/27ths of a gallon of soup.

You need two-thirds of a tonne of lead.

Notes on non-standard parenthesis uses in this answer:

(A/B) is a non-optional term, but can be either A or B. e.g. "(he/she) rode the bike" must include either he or she.*

{variable} is a term to replace with anything from that category. e.g. "{proportion} of a pound" may be "quarter of a pound" etc.

### Special case for half (idioms)

It's worth mentioning that in some cultures, such as British English - it would also be appropriate to drop the "a" in "a half".

Moreover, (in some/most cultures) when talking about halves - this is a special case where you can omit the of or even of a. This is simply due to common phrasing, there is no solid rule that makes this possible.

For halves, you can for example write:

You need half a liter of water.

But it is not the case for all fractions. You would not hear "a third-pound" used to name a measure, partly because it is confusing - if you said "add a third pound to the mix" in a recipe it sounds like you have already added two pounds!

Note that when using half without of, you will always use half a {unit} and never half one {unit}.

Examples:

You need half of a pound of potatoes.

You need half a pound of potatoes.

You need half of the pound of potatoes.

You need a half-pound of potatoes.

You need half a pound of flour.

### Case with the (definite article)

It is usually wrong to say

you need half of the pound of potatoes

But I can write a recipe that would need that construction:

Potato Pie

1. one pound of potatoes plus one small potato
2. 400 grams of flour
3. 500 ml water

• Parboil the potatoes in the water
• Mash half of the pound of potatoes
• Mix the mashed potatoes with the flour
• Slice the other half of the potatoes
• ...
• Cut the last potato into wedges and decorate the pie

In this case, you are referring back to not just a certain weight of potatoes in general, but a specific instance of potatoes that you already have in your context.

This is a much less common usage but not incorrect.

Credits to Bilkokuya, arp and Astralbee for their answers.

• I hope everyone is happy with this summary. Jun 9, 2018 at 9:06