The correct answers are when and after.
Use when to introduce a specific event in the past simple that interrupts an ongoing background action in the past continuous ("were feeding... when the alarm went off").
Use after to show that an action (running away) logically followed a previous completed event (the vault being breached).
Adverb
- ✅ She sings beautifully — ❌ She sings beautiful
- ✅ He drives carefully — ❌ He drives careful
- ✅ They arrived late — ✅ a late train (same form, both roles)
- ✅ She works hard — ❌ She works hardly (different meaning!)
The -ly words are adverbs — they modify verbs, adjectives, or other adverbs, telling you how, when, where, or to what degree.
Pattern: most adjectives become adverbs by adding -ly, but watch the exceptions — fast, hard, late, well — that keep the same shape or change meaning entirely.
Clause and sentence
- I went home. — simple sentence (one clause)
- I went home, and she stayed. — compound sentence (two clauses + conjunction)
- Because it rained, we stayed inside. — complex sentence (dependent + independent)
- She left; he stayed. — two independent clauses joined by semicolon
Clause and sentence covers how clauses combine into sentences — including conjunction choice, subordination, punctuation between clauses, and sentence types (simple, compound, complex).
Pattern: every sentence is built from one or more clauses. How you join them determines the sentence type and the punctuation you need.
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.
Conjunction
- ✅ I was tired, but I stayed. — coordinating (links two equal clauses)
- ✅ I stayed because I was needed. — subordinating (introduces dependent clause)
- ✅ Although it rained, we went out. — subordinating (front position)
- ❌ I was tired, because. — incomplete (subordinating conjunction needs a clause after it)
Conjunctions connect words, phrases, or clauses. Coordinating (and, but, or, so, yet, for, nor) join equals; subordinating (because, although, if, when, while) introduce dependent clauses.
Pattern: coordinating = equal partners, same grammatical weight. Subordinating = one clause depends on the other for its meaning.
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.
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.