English Grammar Rules: Plurals, Tenses, and Modals

English Grammar Essentials

Plural Noun Formation

Regular Plurals: Most nouns form plurals by adding ‘-s’: dog → dogs. Nouns ending in vowel + ‘o’ and new words also add ‘-s’: pianos, photos, kimonos, videos, kilos, studios.

Exceptions: Nouns ending in ‘-sh’, ‘-ch’, ‘-s’, ‘-x’, ‘-z’ add ‘-es’: buses, kisses, brushes, watches, boxes. Some nouns ending in ‘-o’ also add ‘-es’: tomatoes, potatoes, heroes.

Consonant + ‘y’: Change ‘y’ to ‘i’ and add ‘-es’: baby → babies, lady → ladies, fly → flies. Exception: donkeys, boys, days (vowel + ‘y’).

Irregular Plurals: Words ending in ‘-f(e)’ change to ‘-ves’: wife → wives, knife → knives, wolf → wolves, shelf → shelves, leaf → leaves, thief → thieves.

Other Irregular Plurals: Man → men, Woman → women, Tooth → teeth, Mouse → mice, Louse → lice, Foot → feet, Ox → oxen, Child → children.

Latin/Greek Plurals: hypothesis → hypotheses, analysis → analyses, criterion → criteria, phenomenon → phenomena, stimulus → stimuli.

After Link Verbs: (be, seem, look, become, get) use predicative adjectives: V-value, S-size, A-age, T-temperature, SH-shape, C-colour, O-origin, M-material; the blind, the old, the poor, the rich, the young, the unemployed.

Comparative and Superlative: long → longer → longest, big → bigger → biggest, late → later → latest, thin → thinner → thinnest, dry → drier → driest, lucky → luckier → luckiest, early → earlier → earliest, pretty → prettier → prettiest. Exceptions: Proper and eager (use more/most).

Verb Tenses

Present Simple

Used for general facts and repeated events (habits/routines). Use DO, DOESN’T + base verb.

Present Continuous

(Present Progressive) Used for temporary actions and events happening now. Use verb TO BE + -ING. Cry → cries, Hurry → hurries, Study → studies. Exceptions: Buy → buys, Lay → lays; Miss → misses, Push → pushes, Fix → fixes. have → has / go → goes / do → does.

Past Simple

Used for finished states, events, and actions in the past. Also describes habitual past actions. Use -ED or irregular forms, DID.

Past Continuous

Used to describe an action in progress in the past. Use WAS/WERE + -ING.

Present Perfect

Used to connect a past action with the present. Expresses achievement and number of things. Use HAVE/HAS + past participle ( -ED or 3rd form). Use SINCE/FOR.

Future with WILL

Used for predictions and spontaneous decisions. Often used with ‘probably’, ‘expect’, ‘think’.

Future with BE GOING TO

Used for plans and predictions based on present evidence.

Future Perfect

Used to say something will be completed by a certain time. Use WILL HAVE + past participle (-ED or 3rd form).

Adverbs of Time

JUST: Describes a very recent event. ALREADY: Describes something that happened sooner than expected.

Modal Verbs

MUST

Expresses deduction or certainty.

CANNOT/CAN’T

Expresses certainty in negative sentences, indicating something is improbable.

DON’T HAVE TO

Indicates something is unnecessary.

MUSTN’T

Indicates something is prohibited.

SHOULD/OUGHT TO

Used to give advice or opinions.