Simple Past: Subject + V2 — completed action at a specific time in the past.

Past Continuous: Subject + was/were + V1+ing — action in progress at a specific time in the past.

Past Perfect: Subject + had + V3 — an action completed before another past action.

Past Perfect Continuous: Subject + had been + V1+ing — an action ongoing before another past action.

• Simple Past: He visited Karachi last year.
• Past Continuous: She was cooking when I arrived.
• Past Perfect: They had left before we came.
• Past Perfect Continuous: He had been sleeping for hours before she woke him.

Simple Future: will/shall + V1 — prediction or decision made at time of speaking.

Future Continuous: will be + V1+ing — action in progress at a specific future time.

Future Perfect: will have + V3 — action completed before a certain future time.

Future Perfect Continuous: will have been + V1+ing — ongoing up to a point in the future.

Sequence of Tenses ensures consistency of tenses throughout a paragraph or complex sentence. If the main clause is in the past, dependent clauses should also use past forms. Key rules: (1) Main clause Present → Any tense in subordinate. (2) Main clause Past → Past tense in subordinate. (3) Universal truths remain in Simple Present. (4) Unreal conditions use Past/Past Perfect.

Nouns name people, places, things, or ideas. Types: (1) Countable: can be counted (book, pen — a book, three books). (2) Uncountable: cannot be counted (water, rice, advice, information). (3) Abstract: ideas/qualities (love, honesty, beauty). (4) Collective: group of people/things (team, flock, bunch, committee).

Pronouns replace nouns. Key types: Relative (who, whom, whose, which, that) — connect clauses. Reflexive (myself, yourself, himself, herself, itself, ourselves, yourselves, themselves) — reflect back on the subject. Who = subject, Whom = object. Whose = possession. Which = things. That = defining clauses only.

Adjectives describe nouns. Degrees of comparison: (1) Positive: describes without comparison (tall, beautiful). (2) Comparative: compares two things, add -er or use "more" (taller, more beautiful). (3) Superlative: compares three or more, add -est or use "most" (tallest, most beautiful). Irregular: good-better-best, bad-worse-worst, many-more-most.

Adverbs modify verbs, adjectives, or other adverbs. Types: (1) Manner (how): quickly, carefully, well. (2) Place (where): here, there, outside. (3) Time (when): now, soon, yesterday, already. (4) Frequency (how often): always, usually, often, sometimes, rarely, never.

Prepositions show relationships between nouns/pronouns and other words. Types: (1) Time: at (specific time), on (days/dates), in (months/years/longer periods). (2) Place: at (point), on (surface), in (enclosed area). (3) Direction: to, into, onto, towards, from, through.

Conjunctions join words, phrases, or clauses. (1) Coordinating (FANBOYS): For, And, Nor, But, Or, Yet, So — join equal elements. (2) Correlative: used in pairs — either...or, neither...nor, both...and, not only...but also, whether...or.

The verb must agree with its subject in number and person. Key rules: (1) Singular subject → singular verb. (2) Plural subject → plural verb. (3) Collective nouns → singular verb (usually). (4) Indefinite pronouns (everyone, nobody) → singular. (5) Either/Neither → singular. (6) Subjects joined by "and" → plural. (7) Subjects joined by "or/nor" → verb agrees with nearer subject.

Determiners specify nouns. Articles: "a" (before consonant sounds), "an" (before vowel sounds), "the" (specific/known). Quantifiers: some (affirmative), any (negative/question), much (uncountable), many (countable), a lot of (both), few/little (small amount), several (more than two).

Modals express ability, permission, obligation, possibility, and advice. Can: ability/permission (present). Could: ability (past)/polite request. May: formal permission/possibility. Might: less certain possibility. Must: strong obligation. Should: advice/mild obligation. Would: polite request/habit in past. Shall: formal future/offer.

Active Voice: Subject does the action (Ali wrote the letter). Passive Voice: Subject receives the action (The letter was written by Ali). Rules: Object becomes Subject. Verb → be + V3. Subject → by + agent. Tense is maintained. If subject is indefinite, "by" phrase is omitted.

Direct Speech: Exact words in quotes. Indirect Speech: Reported words without quotes. Changes: (1) Tense shifts back (Present→Past, Past→Past Perfect). (2) Pronouns change. (3) Time expressions: now→then, today→that day, tomorrow→the next day, yesterday→the previous day. (4) "Said to" → "told".

Main Clause (Independent): Has a subject and verb and makes complete sense alone. Subordinate Clause (Dependent): Cannot stand alone; depends on the main clause. Introduced by subordinating conjunctions: because, although, when, if, since, while, after, before, unless, until, as, though.

Relative clauses modify nouns. (1) Defining (Restrictive): identifies the noun — no commas, can use "that". (2) Non-defining (Non-restrictive): adds extra info — use commas, cannot use "that". Relative Pronouns: who/whom (people), which (things), whose (possession), that (defining only).

Zero Conditional: If + Present, Present — universal facts. First Conditional: If + Present, will — real/possible future. Second Conditional: If + Past Simple, would — unreal/imaginary present. Third Conditional: If + Past Perfect, would have + V3 — impossible past situation.

A noun clause functions as a noun — it can be a subject, object, or complement. Introduced by: that, whether, if, who, what, why, how, when, where. Examples: Subject: That she won surprised us. Object: I know that he is honest. After prepositions: Tell me about what you saw.

Adverbial clauses modify verbs like adverbs. Types: (1) Time: when, while, before, after, until, since, as soon as. (2) Reason: because, since, as. (3) Contrast: although, though, even though, whereas, while. (4) Condition: if, unless, provided that. (5) Purpose: so that, in order that.

Commas are used: (1) In lists: I bought apples, mangoes, and grapes. (2) After introductory phrase: In the morning, she exercises. (3) In compound sentences before coordinating conjunctions: She was tired, but she continued. (4) In non-defining relative clauses. (5) With direct address: Ali, please sit down. (6) With dates and addresses.

Semicolon (;): Joins two related independent clauses without a conjunction. Use before transitional words: however, therefore, moreover. Colon (:): Introduces a list, quote, or explanation. Use after an independent clause. Examples: She was tired; she still finished the work. The recipe requires: flour, sugar, and eggs.

Apostrophes have two uses: (1) Possession: Singular noun + 's (Ali's book). Plural noun ending in s: add only ' (girls' school). Irregular plural + 's (children's toys). (2) Contractions: it's = it is, you're = you are, they're = they are, don't = do not, can't = cannot. Note: its (no apostrophe) = possessive pronoun.

Capitalize: (1) First word of every sentence. (2) Proper nouns: names of people, places, organizations (Ali, Lahore, United Nations). (3) Titles before names: Mr., Dr., President. (4) Days, months (not seasons). (5) Languages and nationalities. (6) First word of a direct quote. (7) The word "I" (always).

Gerund: V+ing used as a noun (Swimming is fun. I enjoy reading.). Infinitive: to + V1 (I want to go. He decided to leave.). Verbs followed by gerund only: enjoy, avoid, finish, suggest, mind, consider, keep. Verbs followed by infinitive only: want, hope, decide, plan, agree, refuse, promise.

Participles are verb forms used as adjectives. Present Participle: V+ing (a running horse, the burning house). Past Participle: V3 (a broken window, the stolen car). Participial Phrase: a group of words beginning with a participle (Running fast, she won the race). Dangling Participle: occurs when the participial phrase does not logically modify the subject.

Question tags are short questions added to statements to seek confirmation. Rules: (1) Positive statement → Negative tag. (2) Negative statement → Positive tag. (3) Use the same auxiliary verb as in the statement. (4) Pronoun replaces the subject. Examples: She is coming, isn't she? He can't swim, can he? They have finished, haven't they?

Phrasal Verbs are combinations of a verb + particle (preposition/adverb) that create a new meaning. Common phrasal verbs: break down (stop working), look up (search), carry on (continue), give up (stop trying), look after (take care of), run out of (exhaust supply), turn up (arrive), put off (postpone), get along with (have good relations), find out (discover).

Homophones: same pronunciation, different spelling and meaning (their/there/they're, to/two/too, hear/here, know/no, write/right, wear/where). Homonyms: same spelling AND pronunciation, different meanings (bank: river bank vs financial bank; fair: just/exhibition/skin tone; bat: cricket bat/flying mammal).

Transformation changes sentence structure without changing meaning. Types: (1) Affirmative → Negative (using not, never, no). (2) Assertive → Exclamatory (What a...! How...!). (3) Assertive → Interrogative. (4) Degree of Comparison (Positive → Comparative → Superlative). (5) Simple → Compound → Complex.