I’ve noticed several uses of “works” and “equipments” in engineering documents lately, and I have been whacking the “s” off the end of them as I edit. I did a little research as to why so I could explain it fully to y’all.
It turns out that there are two kinds of nouns: countable and uncountable. Countable nouns have plurals, such as wells, valves, flanges, etc. Uncountable nouns do not have plurals. If you look up the word “equipment” in the dictionary, it does not have a plural listed because it refers to a quantity of unspecified stuff, “a set of articles or resources serving to equip a person or thing,” as Webster defines it. A set is singular.
Think of the word “rice,” which is another example of an uncountable noun. (Yes, you could actually sit down and count each grain of rice, but then we would have to send the nice little men in the little white coats to come and take you away, ha-ha.) If you ate just one grain, you wouldn’t say “I ate a rice,” and you certainly don’t say “I ate my rices.”
Equipment is used in the same manner. You wouldn’t say “We installed an equipment,” or “We installed three equipments.” You would probably say: “We installed three pieces of equipment.” Equipment is uncountable, and thus is always singular.
Some nouns are both countable and uncountable, and therefore can have both singular and plural forms.
Examples: Food and foods, candy and candies, coffee and coffees, sand and sands.
Note that the first word of each of these pairs describes a quantity of unspecified stuff much like “rice” and “equipment.” Thus the singular form is the uncountable form.
The second word in each of these pairs refers to multiple individual things (countable), so the plural form is used.
This brings us to work vs. works. Work is the uncountable form. We do the work, the work gets done. Again, it is a quantity of unspecified stuff.
However, the plural form “works” is the countable form, and this refers to individual pieces of work, such as works of art. Here are four other cases where the plural “works” can be used:
1) A mechanism or machine; the means by which something happens; workings.
Example: A single sand grain can really mess up the works of a Swiss watch.
2) A factory or similar collection of buildings, such as steel works.
Example: When Hurricane Ike knocked out the power, Houston’s water works shut down.
3) All the available toppings or accoutrements.
Example: I’ll have a hotdog with the works.
4) An act associated with moral or religious standing.
Example: Mother Teresa was known for her good works in India.
So, if you are completing the work, you are finishing up the job effort. If you are completing the works, you are either finishing up the machine, the factory, or the whole kit and caboodle.