Tài liệu Oxfore guide to english grammar part 56 pdf

294 Consonant + y
294 Consonant + y
When a word ends in a consonant + y, the y changes to ie before s.
study studies lorry lorries
Before most other endings, the y changes to i.
study studied silly sillier lucky luckily
happy happiness
We do not change y after a vowel.
day days buy buyer stay stayed
NOTE
a The possessive forms are singular noun + apostrophe + s, and plural noun + apostrophe.
the lady's name the ladies' names
b A one-syllable word usually keeps y before ly: shyly, slyly, dryly/drily.
c We do not change y when it is part of a person's name: Mr and Mrs Grundy the
Grundys.
d We do not change y in by: stand-bys, lay-bys.
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2 We keep y before i.
copy copying hurry hurrying
NOTE
We change ie to y before ing.
die dying lie lying
But pay, lay and say have irregular ed-forms: paid
Also day daily.
, laid , said
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38
Irregular noun plurals
295 Summary
Most countable nouns have a regular plural in s or es.
hands dates buses.

For details of spelling and pronunciation, • 290.
But some nouns have an irregular plural. Here are some examples.
Vowel and consonant changes • 296
man men wife wives
Nouns which do not change in the plural • 297
one/two aircraft one/two sheep
Irregular plural endings. • 298
children criteria stimuli
NOTE
a We also use men and women in words like Frenchmen, sportswomen.
b The plural people is more usual and less formal than persons.
Several people were waiting for the lift.
A maximum of six persons may occupy this lift.
A people is a large group such as a nation.
The Celts were a tall, fair-skinned people.
One day the peoples of this world will live in peace.
2 With some nouns we change f to v and add es/s.
loaf loaves thief thieves life lives
Also: calves, halves, knives, leaves, shelves, wives, wolves
NOTE
Some other nouns in f/fe are regular: chiefs, beliefs, cliffs, roofs, safes. A few have alternative
forms, e.g. scarfs /scarves.
1 Some plurals are formed by changing the vowel sound.
foot feet goose geese man men
tooth teeth mouse mice woman
women
296 Vowel and consonant changes
5 The usual plural of penny is pence, e.g. fifty pence. Pennies are individual penny
coins.
297 Nouns which do not change in the plural

Some nouns have the same form in the singular and plural.
Singular: One aircraft was shot down.
Plural: Two aircraft were shot down.
These nouns are aircraft, hovercraft, spacecraft etc; some animals, e.g. sheep, deer,
some kinds offish, e.g. cod, salmon; and some nouns ending in s, e.g. headquarters,
means. • 154(3)
NOTE
a Some measurements (e.g. pound, foot) can be singular after a plural number, e.g. two
pound/ pounds fifty.
b For six hundred and twenty, • 191(1) Note c.
analysis analyses crisis crises hypothesis hypotheses
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298 Irregular plural endings
3 Some nouns have a regular written plural in ths, but the pronunciation of th
changes.
path
paths
Also: mouths, youths (= young people)
NOTE
Some other nouns in th are regular: months, births, deaths
. Some have alternative forms,
e.g. truths
or
4 The plural of house is houses
298 Irregular plural endings
1 en
child
children ox oxen
2 a
3 i

criterion criteria phenomenon phenomena medium media
curriculum curricula
NOTE Some nouns in on and um are regular, e.g. electrons, museums.
5 es
4 ae
formula formulae / formulas
stimulus stimuli cactus cacti /cactuses
nucleus nuclei / nucleuses
NOTE Some nouns in us are regular: choruses, bonuses.
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39
Irregular verb forms
299 Summary
A regular verb takes the endings s, ed and ing. For example, base form look,
s-form looks, past tense looked, ing-form looking and past/passive participle
looked. For more details, • 58.
List of irregular verbs • 300
Some verbs have ah irregular past tense and participle.
Base form: Did you write the letter?
Past tense: I wrote the letter yesterday.
Past participle: I've written the letter.
We also use the irregular forms after a prefix such as re, un, out, mis.
I've rewritten the letter. He undid the knot.
Special participle forms • 301
Some special participle forms come before a noun.
a drunken riot
300 List of irregular verbs
Base form Past tense Past/passive participle
Base form Past tense Past/passive participle
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300 List of irregular verbs