Article

• ✅ an hour — ❌ a hour (vowel sound → an)
• ✅ a university — ❌ an university (consonant sound /j/ → a)
• ✅ I love coffee — ❌ I love the coffee (generic uncountable → zero article)
• ✅ the sun — ❌ a sun (unique referent → the)

Articles (a/an, the, and the zero article) signal whether a noun is specific or general. A/an introduces something new; the points to something already known or unique.

Pattern: a/an = "one of many, first mention." The = "you know which one." Zero article = generic or uncountable.

Comparative and superlative

• ✅ She is taller than me. — ❌ She is more taller than me. (double comparative)
• ✅ This is the most interesting book. — ❌ This is the interestingest book.
• ✅ He did better than expected. — ❌ He did more good than expected. (irregular)
• ✅ That's the worst idea ever. — ❌ That's the baddest idea ever.

Comparatives compare two things (-er or more); superlatives pick the extreme of three+ (-est or most). Short adjectives use -er/-est; longer ones use more/most. Never combine both.

Rule: one or two syllables → -er/-est (with exceptions). Three+ syllables → more/most. Irregulars (good/better/best, bad/worse/worst) must be memorised.

Countable and uncountable

• ✅ some advice — ❌ an advice / advices (uncountable → no article, no plural)
• ✅ a piece of furniture — ❌ a furniture / furnitures
• ✅ How much water? — ❌ How many water? (uncountable → much)
• ✅ fewer people — ❌ less people (countable plural → fewer)

English nouns are either countable (take a/an, form plurals, use many/few) or uncountable (no plural, use much/little). The choice is partly arbitrary and must be memorised.

Test: can you put a number in front? Three chairs → countable. Three furnitures ❌ → uncountable. Use a unit phrase instead: three pieces of furniture.

Determiner

• ✅ The cat sat on a mat. — articles as determiners
• ✅ My sister has three dogs. — possessive + numeral as determiners
• ❌ I went to the home. — wrong (idiomatic: I went home — no determiner)
• ❌ She is a good student. ✅ vs She is good student. ❌ — missing determiner

A determiner sits before a noun to specify which, how many, or whose. Types include articles, demonstratives, possessives, and quantifiers.

Rule: most singular countable nouns in English require a determiner — a cat, the cat, my cat, this cat. Dropping it (cat sat on mat) breaks the sentence.

Noun

• The cat sat on the mat. — concrete nouns (things you can touch)
• Happiness is important. — abstract noun (idea/quality)
• London is beautiful. — proper noun (specific name, capitalised)
• I need some information. — uncountable noun (no a/an, no plural)

A noun names a person, place, thing, idea, or quality. Nouns determine article choice, verb agreement, and pronoun reference. Types: common/proper, concrete/abstract, countable/uncountable.

Test: can you put the or a before it? Can you make it plural? If yes to either → it's functioning as a noun.

Past tense

• I walked home. — simple past (completed action)
• I was walking when it rained. — past progressive (in progress)
• I had already left when she arrived. — past perfect (earlier past)
• I had been waiting for an hour. — past perfect progressive (duration up to a past point)

Four past tense forms: simple past (done), past progressive (was happening), past perfect (had already happened), past perfect progressive (had been happening). Each encodes different timing relative to other past events.

Pattern: simple past = the story's main timeline. Past progressive = background action. Past perfect = flashback to something even earlier.

Phrase

• the red car — noun phrase (functions as one noun unit)
• on the table — prepositional phrase
• has been running — verb phrase
• very quickly — adverb phrase

A phrase is a group of words that functions as a single unit WITHOUT a subject + verb pair. Types: noun phrase, verb phrase, prepositional phrase, adjective phrase, adverb phrase.

Key distinction: a phrase lacks a subject-verb pair. If it has subject + verb → it's a clause, not a phrase. Phrases are the building blocks clauses are made of.

Present tense

• I work here. — simple present (habit/permanent)
• I am working now. — present progressive (happening right now)
• I have lived here for 10 years. — present perfect (started past, still true)
• I have been waiting for an hour. — present perfect progressive (duration up to now)

Four present tense forms: simple (habits/facts), progressive (now/temporary), perfect (past → present relevance), perfect progressive (ongoing duration). Each encodes a different relationship between the action and the present moment.

Trap: "I am living here for 10 years" ❌ — started in the past + still true = present PERFECT (have lived/have been living), not progressive.

Subject

• ✅ The list of items is wrong. — subject = list (singular), not items
• ❌ The list of items are wrong. — trapped by nearest noun
• ✅ Running is good exercise. — gerund as subject
• ✅ What he said surprised me. — clause as subject

The subject is the noun/pronoun/phrase before the verb that controls its number and person. Finding the true subject — especially through prepositional phrases — is the key to subject-verb agreement.

Rule: strip away prepositional phrases between subject and verb. Whatever's left is the true subject. The list (of items) is wrong.

Verb

• walk → walk / walks / walked / walked / walking (5 forms, regular)
• go → go / goes / went / gone / going (5 forms, irregular)
• be → am/is/are/was/were/be/being/been (8 forms)
• can → can / could (modal: only 2 forms, no -s, no -ing)

A verb is the one word class every English sentence requires. Carries tense (when), aspect (duration), mood (attitude), and voice (active/passive). Regular verbs add -ed; ~200 irregular verbs have unpredictable past forms.

Key insight: fix your verbs and most grammar problems disappear. Wrong tense, wrong agreement, wrong form — verb errors account for the majority of grammatical mistakes.

Verb tense

Verb tense = time (past/present/future) × aspect (simple/progressive/perfect) = 12 forms. Each slot has a specific job — not just "when" but "how the action relates to its time frame."

Key insight: most learners don't need all 12 at once. Simple covers 80% of communication. Add perfect and progressive as needed.

Perfect tense

• ✅ I have lived here for ten years. — present perfect (started past, still true)
• ❌ I live here for ten years. — wrong (simple present can't bridge past→now)
• ✅ She had finished before I arrived. — past perfect (earlier past)
• ✅ They will have left by noon. — future perfect (completed before future point)

The perfect = have + past participle. Connects an action to a reference point in time. Present perfect bridges past→now. Past perfect marks "earlier past." Future perfect marks "done before a future deadline."

Rule: if the action started in the past and is still relevant now → present perfect (have done). If two past events and you need the earlier one → past perfect (had done).

Progressive tense

• ✅ I am working in London. — temporary, happening now
• ✅ I work in London. — permanent/habitual (simple)
• ❌ I am knowing the answer. — stative verb, can't be progressive
• ✅ She was reading when I arrived. — past progressive (in progress at that moment)

The progressive = be + -ing. Marks actions as ongoing, temporary, or in-progress at a reference time. NOT used with stative verbs (know, believe, own, want, like) unless meaning shifts.

Rule: is the action temporary/in-progress right now? → progressive. Is it a permanent fact, habit, or schedule? → simple. Is it a stative verb? → almost never progressive.

Simple tense

• ✅ I go to work every day. — present simple (habit)
• ✅ She went home yesterday. — past simple (completed action)
• ✅ I will call you later. — future simple (promise/decision)
• ✅ Water boils at 100°C. — present simple (general truth)

The simple aspect is the default, unmarked verb form. Present simple = habits, facts, schedules. Past simple = completed actions. Future simple = predictions, promises, decisions. No auxiliary needed (except will for future and do for questions/negatives).

Rule: if the action is a fact, habit, completed event, or scheduled future — and you don't need to emphasise it being in-progress or connected to now → simple tense.

B1 | Intermediate

• ✅ If I had more time, I would travel more. — second conditional
• ✅ The bridge was built in 1920. — passive voice
• ✅ She said she was tired. — reported speech with backshift
• ✅ Although it rained, we enjoyed the trip. — complex sentence with concession

These are B1 patterns — the CEFR intermediate level. At B1 you link ideas, use passive voice, handle reported speech, and manage second conditional — enough for travel, work basics, and everyday independence.

Marker: if you can explain why something happened and follow a news story, you're B1.

B2 | Upper Intermediate

• ✅ If I had studied harder, I would have passed. — third conditional
• ✅ The report is being reviewed by the committee. — passive progressive
• ✅ Having finished the exam, she left. — participle clause
• ✅ He denied having taken the money. — complex verb pattern

These are B2 patterns — the CEFR upper-intermediate level. At B2 you handle mixed conditionals, all passive forms, participle clauses, and can argue a point clearly. This is the level most universities and employers require.

Marker: if you can write a structured essay and debate an abstract topic, you're B2.

Medium

• If I were you, I would apologise. — one rule (second conditional), but distractors like was tempt you
• Answers require active thought, not instant pattern recognition
• Vocabulary and context are realistic, not artificially simplified
• Usually tests one rule, but the wrong answers are plausible

Medium marks middle-difficulty challenges: A2–B1, one rule tested, but with realistic distractors that require genuine understanding.

Use "Medium" when Easy feels too obvious but Hard feels overwhelming. This is where most productive learning happens — the sweet spot of difficulty.