Singular invariables (singularia tantum). Here belong:
1) material nouns: sand, gold;
2) abstract nouns: music, homework;
3) substantivized adjectives with abstract meaning: the inevitable, the evident;
4) proper names: London, the Thames;
5) some diseases: diabetes, mumps, measles, rabies, rickets, shingles;
6) some games: bowls, billiards, draughts, darts, skittles;
7) the word news;
8) subject names in - ics: aerobics, classics, genetics, linguistics, mathematics, phonetics, statistics, etc. Some of these nouns are occasionally used in the plural, when you are talking about a particular person’s work or activities: His politics are uncertain. The statistics are optimistic.
9) some proper nouns: Athens, Brussels, Wales, the United States, the United Nations.
10) collective nouns: money, advice, weather, jewellery, information, fruit. But: the fruits of my investigation. This drink is made from four tropical fruits. The tomato is a vegetable, not a fruit.
Plural invariables
1. Summation plurals (= nouns denoting objects consisting of two parts): braces, shorts, glasses, jeans, leggings, tights, trousers, scissors, scales, binoculars, etc.
Note. When you want to refer to a single piece of clothing or a single tool you can use “some” or “a pair of” in front of the noun. You can refer to more than one item by using a number or a quantifier with “pairs of”. When you use “a pair of” with a noun in the plural form, the verb is singular if it is in the same clause, and plural if it is in the following relative clause: A new pair of new shoes brings more happiness. He put on a new pair of shoes, which were waiting for him.
2. Substantivized adjectives denoting people: the rich, the poor, the old, the young, the English.
3. Miscellaneous nouns: wages, sweepings, the contents of a book (but the silver content of the coin), archives, arms, ashes, customs, earnings, goods, greens, looks, stairs, manners, minutes, outskirts, riches, surroundings, thanks, the Middle Ages.
4. Some proper names: The Netherlands, the Midlands, the Hebrides], the East Indies.
Note the singular and the plural form of the noun in the following patterns:
Don’t go into detail. ― Не вдавайтесь в детали. She described it in (great) detail. ― Она описала это в (мельчайших) подробностях. He has a good eye for detail. ― Он замечает все детали.
Note 1. Compound numerals with –one: twenty-one, thirty-one, etc. take a noun in the plural. Twenty-one students were present at the lecture. ― На лекции присутствовал двадцать один студент.
Note 2. The nouns grapes, carrots, beets, potatoes, onions, radishes, etc. are always plural when used collectively. Lemons contain a lot of vitamin C.
Note 3. There are a few nouns in English which have only the plural form and lack the singular (pluralia tantum nouns). But they happen to be homonyms of nouns which are used in both forms, i.e. regular plural. These nouns are:
1) colour — colours (= hues) — colours (= regimental flags)
2) a force — forces (= powers) — forces (= an army)
3) a custom — customs (= habits) — customs (= taxis on imported goods)
4) a draught — draughts (= currents of air) — draughts (= a game)
5) a glass — glasses (= vessels for drinking from) — glasses (= spectacles)
6) a manner — manners (= ways) — manners (= behaviour)
7)a moral — morals (= lessons of a story) — morals (= standards of behaviour)
8) a minute — minutes (= spaces of time) — minutes (= secretary’s record of proceedings)
9) a quarter — quarters (= forth parts) — quarters (= lodgings)
Some nouns which belong to the singularia tantum group are occasionally used in the plural form for stylistic reasons suggesting a great quantity or extent: the sands of the Sahara; the snows and frosts of the Arctic; the waters of the Atlantic; the blue skies of Italy; in all weathers, etc.
Note 4. Some nouns which are singular in English are plural in Russian: applause, cream, debate, fighting, evidence, gossip, hair, ink, knowledge, progress, a gate, a funeral, a watch, a sledge, a race, a vocation.