6. Work out the rules how to build the plural of irregular nouns which retain their original Greek or Latin forms by analyzing examples:

EXAMPLES	rules
focus-foci; nucleus – nuclei	Some nouns ending in “us” have plurals ending in ______________
aquarium - aquaria; memorandum – memoranda, genus – genera	Some nouns ending in “um” have plurals ending in ______________
criterion – criteria, phenomenon-phenomena	Some nouns ending in “on” have plurals ending in ______________
analysis – analyses; axis – axes, appendix – appendices/appendixes, matrix – matrices	Most nouns ending in “is” have plurals in which the “is” is replaced by ______________
larva- larvae	With some nouns ending in “a”, the plurals are formed by adding ______________
automation – automata/automatons; corpus – corpora; ; tempo – tempi/tempos; virtuosu – virtuosi/virtuosos	Other nouns form their plurals __________

7. Check up whether your rules work by making the following nouns plural and then consulting the dictionaries. Remember that some of them, e.g. formula, amoeba, and nebula, also have less formal plurals ending in “s”:

basis – _________; radius – _________ ; formula - _________ , crisis – _________; referendum – _________; stimulus – __________; spectrum – _________; diagnosis – _________; antenna- _________ , neurosis – _________; index – ___________; stratum – _________ ; hypothesis – _________; phenomenon –_________; parenthesis – _________.

Golden Rules

• Singular nouns for groups of people often have plural verbs and pronouns in British English, especially when we are talking about personal kinds of action. Compare:

My family are very angry with me: they think I should earn my living.

The average family has 3.5 members: it is much smaller than in 1900.

The team are going to lose again. They're useless.

A cricket team is made up of eleven players, including its captain.

• The following singular expressions also usually have plural verbs:

a number of... the majority of... a couple of... a group of... a lot of+ plural noun/pronoun, the rest of+ plural noun/pronoun.

A number of us are truly excited about it.

The majority are good team workers.

There are a couple of tasks to be done today.

A lot of them were beyond the deadline.

The rest of our employees are on sick leave.

• Some plural expressions have singular verbs:

names of quantities, plural names of countries, compound nouns joined by and, more than one + singular noun.

Fifty dollars is too much to pay.

Two weeks wasn't enough holiday.

The United States is smaller than Canada.

Fish and chips costs £6.

More than one small-scale firm is facing problems.

We also use a singular verb after one of+ plural noun. One of their branches has made a loss.

We can put nouns together in three ways:

1 noun + noun: a shoe shop; a cowboy film

2 preposition structure: the mouth of the river

3 possessive 's structure: my boss's office; Mathew’s idea

Usually, an idea can be expressed in only one of these ways, and it is often difficult to know which is correct. The rules will help, but there are exceptions - this is a very difficult point of grammar.

• We often put one noun in front of another. The first noun is rather like an adjective, and is usually singular, even if the meaning is plural.

a horse race (a kind of race) a race horse (a kind of horse)

a shoe shop (not a shoes shop) a Bristol man

a ten-mile walk (not a ten-miles walk, although you can write a ten miles’ walk)

Articles belonging to the first noun are dropped in this structure.

Officers in the army - army officers, NOT the army officers.

• We use the possessive 's structure especially when the first noun is the name of a person, group of people, organisation, country or animal.

In other cases we generally prefer a structure with of. Compare:

my father's name the name of the book

the firm's structure the structure of plastic

America's influence the influence of alcohol

the dog's leg the leg of the table

We also use the possessive 's structure with common 'time when' expressions, and in expressions of measurement of time.

today's paper tomorrow's weather yesterday's news

a month's holiday three miles' distance (or: three-mile distance)

• Possessives usually replace articles before nouns. We can say the car or Alec's car, but not Alec's the car or the Alec's car.

But a possessive word can have its own article: the boss's car.

Note also: that car of Alec's; a friend of Lou's (like a friend of mine).

We use the double possessive when we want to make the first noun specific, but at the same time show that it is one of several:

I heard the story from a friend of my brother’s. (= from one of my brother’s friends)

We usually use the indefinite article with this pattern. The double possessive is common with pronouns:

Ann is a friend of ours. (= we have several friends. She is one of them.)

Note: We spent the evening at Damon's. ( = ... at Damon's house.)

She's at the hairdresser's. I bought it at Harrod's.

Grammar in Focus