English Grammar Rules, Tenses and Key Usage

English Grammar: Key Forms and Rules

To-Be: to be (be). To-Have: to have (have). Can: ability / power. Must: duty, obligation; deduction + infinitive. May: permission / possibility.

Pronouns, Quantifiers and Demonstratives

Few / Many: e.g., accountants. Little / Much: countless.

Since: from about 1970. For: duration, e.g., for 3 hours (period).

Some: used in affirmative sentences. Any: used in negative and interrogative sentences (but not in affirmative: I have no money).

This: this (singular). These: these (plural). That: that (singular). Those: those (plural).

Auxiliaries and Do/Does/Did

Do / Does / Did: form the auxiliary for negatives and questions. The main verb appears in the base form (infinitive without to).

Articles

a = indefinite article (used with occupations, religions, ideologies). the = definite article.

Use an before vowel sounds: an honest man. Use a before consonant sounds: a teacher.

Gerunds and Prepositions

After the preposition of, the next word often ends in -ing (e.g., of saying). Verb forms that follow prepositions typically use the -ing form.

Too and Also

Too: means also / in addition (used informally). Also: also.

There is / There are

There is: used with singular (1). There are: used with plural (+1).

Tense Forms and Usage

Present Simple

Affirmative: Subject + base verb (infinitive). In 3rd person singular add -s (exceptions: verbs ending in -x, -ch, -sh, -ss add -es). Negative: Subject + do + not + base verb (use does for 3rd person singular). Interrogative: Do + subject + base verb? (Does for 3rd person singular).

Present Continuous

(Unfinished actions, plans, etc.) Affirmative: Subject + am / is / are + verb + -ing. Negative: Subject + am / is / are + not + verb + -ing. Interrogative: Am / is / are + subject + verb + -ing?

Past Simple

(Action completed) Regular verbs: add -ed; irregular verbs: use 2nd column (simple past). Affirmative: Subject + verb (past form). Negative: Subject + did not + base verb. Interrogative: Did + subject + base verb?

Past Continuous

(Simultaneous actions, description) Affirmative: Subject + was / were + verb + -ing. Negative: Subject + was / were + not + verb + -ing. Interrogative: Was / were + subject + verb + -ing?

Present Perfect

(Actions finished or begun in the past that continue or have relevance to the present) Affirmative: Subject + have / has + past participle (3rd column). Negative: have / has + not + past participle. Interrogative: Have / has + subject + past participle?

Present Perfect Continuous

(Most recent actions that have just completed or still continue) Affirmative: Subject + have / has + been + verb + -ing. Negative: have / has + not + been + verb + -ing. Interrogative: Have / has + subject + been + verb + -ing?

Past Perfect

(Actions in the distant past relative to another past point) Structure like present perfect but with had: Subject + had + past participle.

Past Perfect Continuous

(Actions that occurred in the past up until a specified time) Structure: Subject + had + been + verb + -ing.

Future Simple

(Promises, decisions, predictions, warnings, conditional results) Affirmative: Subject + will + base verb.

Future Continuous

(Actions that will be in progress at a future time) Affirmative: Subject + will be + verb + -ing.

Future Perfect

(Actions that will be completed before a specified future time) Affirmative: Subject + will have + past participle (3rd column).

Comparatives and Superlatives

-er: comparative for short adjectives. -est: superlative for short adjectives. More: comparative for longer adjectives. The most: superlative for longer adjectives.

Conditional and Modal Notes

Would: conditional. Would have: conditional perfect.

Prepositions: AT, IN, ON

AT: times (hours) and specific locations and expressions: at school, at night, at the corner. IN: countries, parts of the day, seasons, years: in Brazil, in the morning, in winter, in 1976. ON: floors and streets or days: if you live in an apartment on the second floor; on the corner means on the street; on Thursday; on Easter Day.

Miscellaneous Notes

• Keep verbs in their appropriate form after auxiliaries and modals (infinitive without to after do/does/did and after modal verbs).
• Spelling and regular vs irregular verb forms: regular verbs add -ed; irregular verbs use their specific past and past participle forms.
• Use contractions and negatives appropriately: did not / didn't; have not / haven't; has not / hasn't; will not / won't.

All original content retained and corrected for spelling, grammar, and capitalization. Headings use semantic levels h2-h3-h4 as applicable, and examples have been clarified for accurate usage.