The correct answers are:
- The shadowy figure disappeared into the foggy London night.
- The criminal mastermind eluded the police for six consecutive months.
- The suspects fled the country before we could issue an arrest warrant.
Disappear is strictly intransitive and correctly has no direct object. Elude and flee are transitive verbs here, correctly taking the direct objects "the police" and "the country." Steal is transitive, so the ruby cannot "steal" on its own; it needs a passive voice construction (was stolen). Occur is an intransitive verb meaning "to happen." It cannot take a direct object like "the burglars" (the alarm should
Object
In grammar, an object is the entity a verb acts on. Tom studies grammar — grammar is the object. English distinguishes three types: a direct object (the thing acted on: Sam fed the dogs), an indirect object (the recipient: She sent him a present), and a prepositional object (introduced by a preposition: She is waiting for Lucy).
Knowing whether a verb takes an object — and which kind — is built into transitive and intransitive verb patterns. Pick the wrong pattern and the sentence either dangles or doubles up.
Past tense
The past tense is how English talks about events finished before now. It comes in four flavours: simple past (I walked) for completed events, past progressive (I was walking) for actions ongoing at a past time, past perfect (I had walked) for events before another past event, and past perfect progressive (I had been walking) for ongoing events leading up to a past point.
Choosing the right one is what makes past narratives clear instead of murky. When I arrived, she ate dinner is technically grammatical but means something different than had eaten (already done) or was eating (in progress when you arrived).
Sentence
A sentence is the largest grammatical unit in writing — one or more clauses expressing a complete thought, ending with a period, question mark, or exclamation mark. English sentences come in four structural types: simple (one independent clause), compound (two or more independent clauses joined), complex (independent + dependent clause), and compound-complex (multiple independent + dependent clauses).
Mastering sentence types is what lets you vary rhythm in writing. All-simple sentences read as choppy; all-complex sentences read as dense. Mixing them is what makes prose breathe.
Sentence and structures
The Sentence and structures tag is the umbrella for everything about how words combine in English: sentences, clauses, phrases, and the syntactic relations between them. Topics gathered here include word order, inversion, supplementation, coordination, negation, indirect speech, and deixis and anaphora.
Browse here when you're past parts-of-speech basics and want to understand how full sentences are assembled — the level where punctuation, comma rules, sentence variety, and clause linking all start making sense as one system.
Transitive and intransitive verb
A transitive verb requires an object to complete its meaning (She broke the vase); an intransitive verb can't take a direct object (Rivers flow, Birds fly). Many verbs are ambitransitive — they work both ways with different meanings (She eats lunch / She eats slowly; The window broke / I broke the window).
This distinction matters because using a transitive verb without its object (She broke.) leaves the sentence dangling, and adding an object to an intransitive verb (She slept her bed) breaks it. Knowing each verb's pattern is essential for avoiding common A2/B1 mistakes.
Verb
A verb is a word that expresses an action, a state, or an occurrence — the engine of every English sentence. Most verbs have five forms: base (go), -s form (goes), past tense (went), past participle (gone), and -ing form (going). The verb be is the major exception with eight forms; modal verbs like can and must have fewer.
Verbs carry tense (when), aspect (how it unfolds), mood (the speaker's attitude), and voice (active vs passive). Mastering them is foundational — virtually every other grammar topic depends on getting verbs right.
Passive voice
The passive voice flips a sentence so the object of the action becomes the subject, and the original doer either disappears or moves to a by-phrase: The chef cooked the meal (active) → The meal was cooked by the chef (passive). Formed with be + past participle (was cooked, is being written, had been seen), and works across all tenses.
Use the passive when the action matters more than the doer (The report was filed), when the doer is unknown or obvious (My car was stolen), or to soften criticism (Mistakes were made). Overusing it makes prose feel evasive — careful writers reach for the active voice by default.
Humor
The Humor tag marks questions and challenges where the author has tried — subjectively, deliberately — to make the practice itself entertaining. Expect characters, scenarios, and storylines that play with absurdity: zombies, alien tourists, a chef's disaster, a roommate's complaint. The grammar rule is real; the wrapping isn't.
Humor matters because grammar drills are forgettable. Tying a rule to a story your brain wants to keep makes it stick. Filter by Humor when motivation is what you're short on, not study time.
B2 | Upper Intermediate
B2 is the upper-intermediate level in the CEFR framework, sitting between B1 and C1. At B2 you can read editorials, follow most TED talks without subtitles, and hold extended conversations on abstract topics — including topics outside your everyday life.
Grammatically, B2 means flexible control of mixed conditionals, passive voice across tenses, reported speech with proper backshifting, and participle clauses. B2 is the standard target for university entrance exams (IELTS 5.5–6.5, TOEFL 87–109) and most skilled-migration thresholds — knowing whether you're there shapes your study plan.
Difficulty: Medium
The Medium difficulty tag marks questions and challenges in the middle of the difficulty range — typically suitable for A2 to B1 learners. Expect a single rule with realistic distractors, longer sentences, and contexts where you have to think before answering rather than reading off the obvious choice.
Filter by Medium when you're past the absolute basics and ready to consolidate. It's the level where most lasting progress happens — easy enough that you can finish without exhausting concentration, hard enough that getting it right means you've actually understood.