Complex sentence

• ✅ Because I overslept, I missed the bus. — dependent clause (reason) + independent
• ✅ The man who called is my uncle. — relative clause inside the sentence
• ✅ If it rains, we'll stay inside. — conditional dependent + independent
• ❌ Because I overslept. — fragment (dependent clause alone)

A complex sentence pairs an independent clause with one or more dependent clauses linked by subordinating conjunctions (because, although, if, when) or relative pronouns (who, which, that).

Pattern: independent clause = the main point. Dependent clause = the background, reason, or condition. Move the dependent clause around for emphasis.

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.

Infinitive

• ✅ I want to go. — to-infinitive after want
• ✅ She can swim. — bare infinitive after modal
• ✅ Let me help. — bare infinitive after let
• ❌ I enjoy to read. — wrong (enjoy takes gerund, not infinitive)

The infinitive has two forms: to-infinitive (to go) after verbs like want, decide, plan, hope; bare infinitive (go) after modals and causatives (let, make, help).

Rule: after want, need, decide, plan, hope, expect, agree, refuse → to-infinitive. After can, will, must, let, make → bare infinitive. After enjoy, avoid, finish → gerund, NOT infinitive.

Clause

• I missed the bus. — ✅ independent clause (stands alone)
• Because I overslept. — ❌ fragment (dependent clause, can't stand alone)
• Because I overslept, I missed the bus. — ✅ dependent + independent = complete sentence
• I missed the bus, and I was late. — ✅ two independent clauses joined by and

A clause is a unit built around a verb with a subject. Independent = can stand alone. Dependent = needs an independent clause to complete it.

Test: does the group of words have a subject + verb AND can it be a sentence on its own? Yes → independent clause. Has a subject + verb but feels incomplete → dependent clause.

Word order

• ✅ She (S) eats (V) cake (O). — standard SVO
• ❌ Cake eats she. — SOV (not English)
• ✅ a lovely little old rectangular green French silver whittling knife — adjective order (opinion→size→age→shape→colour→origin→material→purpose)
• ✅ Never have I seen… — inversion after negative adverb

English word order = SVO (subject-verb-object) as default. Adjectives follow a fixed sequence (opinion→size→age→shape→colour→origin→material). Adverb placement varies by type. Deviations signal questions, emphasis, or literary style.

Rule: when in doubt, default to SVO. English position = meaning. Move a word and you change the grammar or the emphasis.

C1 | Advanced

• ✅ Not only did she finish early, but she also helped others. — inversion for emphasis
• ✅ It is the process that matters, not the result. — cleft sentence
• ✅ I insist that he be present. — formal subjunctive
• ✅ Were I to disagree, I would say so. — inverted conditional

These are C1 structures — the CEFR advanced level. At C1 you control inversion, cleft sentences, subjunctive forms, and register-switching fluently across formal and informal contexts.

Marker: if you can restructure a sentence for rhetorical effect without hesitation, you're C1.

Hard

• Had she not intervened, the situation would have escalated. — inverted conditional
• All distractors are grammatically plausible in other contexts
• Multiple rules interact (e.g., tense + aspect + modality)
• Context determines the answer — no single "rule" is enough

Hard marks upper-intermediate to advanced challenges: B2+, interacting rules, edge cases, plausible distractors, and contexts where pattern-matching fails.

Use "Hard" when Easy/Medium feel trivial and you want to test whether you actually understand a rule versus just recognising surface patterns.