Mass nouns

What is a mass noun?
Definition
mass noun

A noun, such as sand, oil, or honesty, that denotes a substance or concept indivisible into countable units and is preceded in English indefinite constructions by modifiers such as some or much rather than a or one.

mass noun

(Linguistics) a noun that refers to an extended substance rather than to each of a set of isolable objects, as, for example, water as opposed to lake. In English when used indefinitely they are characteristically preceded by some rather than a or an; they do not have normal plural forms Compare count noun

That is to say,In English, a mass noun has no plural form, only singular. Contrast this with count nouns, which denote "things". A noun phrase can refer to one or more of these things. A mass noun denotes stuff, or a substance. Stuff, unlike things, is considered to be "divisible". One speaks of removing some stuff from, say, a container. One does not normally speak of a stuff. Some illustrative examples of English mass nouns:

water
furniture
meat
knowledge

Some nouns can have both mass noun and count noun meanings. For example, "laundry" as a mass noun is the stuff you put in the washing machine, i.e. dirty clothes. A "laundry" as a count noun is an establishment which washes clothes, also known as a laundrette. The difference in meaning can be interpreted from whether the item is counted:

"There is laundry on my street." ( must be a mass noun )
"There is a laundry on my street." ( must be a count noun )

This difference is subtle when phrased in the negative:

"There is no laundry on campus."  ( could be either )
"There are no laundries on campus." ( must be a count noun )

Another marker of difference between mass and count nouns is "less" and "fewer":

We have less furniture.
We have fewer chairs.

Many English speakers incorrectly use "less" for both types; in the 1990s several British supermarkets were criticised for their signs above checkouts reading "10 items or less". The correct form is "10 items or fewer": "items" is a count noun, and a mass noun cannot be given a number anyway. A mass noun can be preceded by a count noun: for example "10 pieces of furniture".
The word "data" is often used as a mass noun, especially by people who work with computers, but this usage is still controversial. In formal writing it retains its original grammatical role as the plural of "datum".

By other words,A mass noun is a noun whose referents are not thought of as separate entities.

It may have distinguishing features such as the following:

* The inability to take a plural form
* Cooccurrence with some determiners (such as some and much), but not others (such as the English many)

Discussion

Some nouns may permit treatment as either count or mass nouns.

Example:

In English, salad may be treated as either a count or mass noun, as evidenced by the acceptability of the following expressions:

* many salads
* much salad

Examples (English)

#

The word furniture is a mass noun. It cannot take the plural suffix -s:
# * furnitures

In addition, it can occur with some determiners, but not others:
# the furniture
# much furniture
# some furniture
# * a furniture
# * many furnitures
Source:

Quirk, Greenbaum, Leech, and Svartvik 1985 246