1. Words ending in IN ‘is’

Words ending in ‘is’ form their plurals by changing ‘is’ into ‘es’.

HYPOTHESIS = an idea or explanation for something that is based on known facts but has not yet been proved (परिकल्पना). HYPNOSIS = a mental state like sleep, in which a person’s thoughts can be easily influenced by someone else; e.g. Under deep hypnosis she remembered the traumatic events of that night. (सम्मोहन(METAMORPHOSIS = a complete change; e.g. Under the new editor, the magazine has undergone a metamorphosis. NARCOSIS = a state of stupor, drowsiness, or unconsciousness produced by drugs (अचेतनता). OASIS = a fertile spot in a desert, where water is found ( मरुस्थल के बीच हरित भूमि). PARENTHESIS = Either or both of the upright curved lines, used to mark off explanatory or qualifying remarks in writing or printing (ब्रैकेट). SYNOPSIS = a short description of the contents of something such as a film or book (रूप-रेखा)

2. Words ending in ‘um’

A) Words that form their plurals by adding ‘s’ at the end.

ASYLUM = an institution for the care of people who are mentally ill; e.g. He’d been committed to an asylum. (पागलखाना). EUPHONIUM = a large musical instrument made from brass that you play by blowing into it. MAUSOLEUM = a building in which the bodies of dead people are buried (मकबरा). NOSTRUM = an idea for solving a problem, especially one that is not very good PODIUM = a small platform on which a person may stand to be seen by an audience, as when making a speech or conducting an orchestra (मंच). ROSTRUM = a raised surface on which a person making a speech or a music conductor (= leader) stands) (मंच)

B) Words that form their plurals by changing ‘um’ into ‘a’.

CREMATORIUM = a place where a dead person’s body is cremated (श्मशान). DICTUM = a short statement, especially one expressing advice or a general truth; e.g. He followed the famous American dictum ‘Don’t get mad, get even’. (कहावत). ERRATUM = a mistake in a printed or written document. STRATUM = one of the parts or layers into which something is separated; e.g. The report shows that drugs have penetrated every stratum of American society.

C) Words that form their plurals in two ways; you can either change ‘um’ into ‘a’ or add ‘s’ at the end.

AQUARIUM = a transparent tank of water in which live fish and other water creatures and plants are kept (मछलीघर). SYMPOSIUM = an occasion at which people who have great knowledge of a particular subject meet in order to discuss a matter of interest

3. Words ending in ‘on’

A) Words that form their plurals by changing ‘on’ into ‘a’.

B) Words that form their plurals by changing ‘on’ into ‘s’.

DEMON = an evil spirit

C) Words that form their plurals by changing ‘on’ into ‘s’ or ‘a’.

AUTOMATON = a machine that operates on its own without the need for human control, or a person who acts like a machine, without thinking or feeling; e.g. I take the same route to work every day, like some sort of automaton.

4. Words with no fixed pattern

BANDIT = a thief with a weapon, especially one belonging to a group that attacks people travelling through the countryside (डाकू(CHERUB = an angel that is represented in art as a beautiful, fat, naked child with small wings. DOGMA = a fixed, especially religious, belief or set of beliefs that people are expected to accept without any doubts. FORMULA = as plural form formulae is used by scientists. LIBRETTO = the words that are sung or spoken in a musical work for the theatre. MONSIEUR = a title or form of address used of or to a French-speaking man, corresponding to Mr or Sir. SERAPH = an angel of the highest rank. TEMPO = the speed at which an event happens; e.g. We’re going to have to up the tempo (= work faster) if we want to finish on time.

NOTE-I: AGENDUM is not used in English. AGENDA, though a Latin plural, is treated as singular in English. Plural for AGENDA is both AGENDA and AGENDAS; e.g.

i) What is the agenda today?
ii) The agenda has not been drawn up yet.

NOTE-II: DATA is plural, therefore, we prefer a plural verb for this word generally, but in a certain context it is treated as a collective noun denoting a single body of facts rather than a number of individual points, and therefore use a singular verb in that meaning; e.g.

i) Is that all data we have in all?
ii) What are the data Sir? (used not as collective noun)

NOTE-III: The plural of METROPOLIS is METROPOLISES. There is a big difference in the usage of METROPOLIS and METROPOLITAN. METROPOLIS is a noun whereas METROPOLITAN is an adjective mainly; e.g.

1. i) Mumbai is a metropolis.
ii) There are seven metropolises in India.
iii) The temperature of all the metropolises has been here.

2. i) metropolitan police
ii) metropolitan life
iii) metropolitan culture

[But you can’t say metropolitan city as the term METROPOLITAN itself means relating to a city (very big city). Therefore the following sentences are incorrect.]

INCORRECT: He lives in a metropolitan city.
CORRECT: He lives in metropolis.

INCORRECT: Delhi is a metropolitan city.
CORRECT: Delhi is a metropolis.

We use the word METROPOLITAN as a noun also. METROPOLITAN here means an inhabitant of a metropolis. ; e.g.

I) He is a metropolitan.
II) They are metropolitans.