The correct answers are:
- It is rumored
- the glowing spaceship was reported
- to have vanished
Explanations:
- It is rumored: When using a "that" clause for passive reporting, we must use the dummy subject "It" (It + passive reporting verb + that + clause).
- was reported: The farmers did the reporting in the past, so the spaceship "was reported" (past passive).
- to have vanished: When the subject (the spaceship) is placed at the front of a passive reporting sentence, it must be followed by a "to-infinitive." Because the vanishing happened before or at the time of the reporting, we use the perfect infinitive ("to have vanished").
Passive voice
Active vs passive: active puts the doer first (The dog bit the man). Passive puts the receiver first (The man was bitten by the dog). Neither is inherently wrong — choice depends on what you want to foreground. Scientific/formal writing uses passive deliberately; vague writing uses it accidentally.
Passive voice = be + past participle. Promotes the object to subject. Good for foregrounding the action/result; bad when it hides who's responsible.
Diagnostic: who's doing the action? If unnamed and that matters → bad passive. If unnamed because it's obvious or irrelevant (The building was constructed in 1920) → good passive.
Indirect speech
Direct vs indirect speech: direct speech quotes exact words (She said, "I am tired."). Indirect speech reports the meaning (She said she was tired.). The key difference is backshift — tenses move one step into the past when the reporting verb is past tense.
Indirect speech = reported words without quotation marks. Core mechanism: backshift (present→past, past→past perfect, will→would) + pronoun/time shifts.
Diagnostic: is the reporting verb past (said, told)? → backshift required. Is it present (says, tells)? → no shift needed. Exception: universal truths don't shift (He said the Earth is round).
Infinitive
Infinitive vs gerund: the #1 verb-pattern confusion. Some verbs take only infinitive (want to go ✅), some only gerund (enjoy going ✅), some both with different meanings (stop to smoke ≠ stop smoking). No logical rule exists — learn by verb.
The infinitive = base verb form used non-finitely. To-infinitive (to go) after certain verbs. Bare infinitive (go) after modals and causatives.
Diagnostic: what's the main verb? Check whether it takes to-infinitive, bare infinitive, or gerund. If unsure, try both and see which sounds natural to native speakers.
Clause
Clause vs phrase: a clause has a subject + verb (she runs); a phrase does not (in the morning, running fast). This is the first distinction to make when analysing sentence structure.
A clause is a grammatical unit built around a verb: independent clauses make complete sentences; dependent clauses attach to them as modifiers or complements.
Diagnostic: find the verb. If there's a subject doing or being something → clause. If there's no subject-verb pair → phrase.
Subject
Subject vs object: the subject does or is; the object receives. She (subject) hit him (object). In English, position decides: subject comes before the verb, object after. Unlike inflected languages, English rarely marks subjects with case (exception: pronouns — I vs me).
The subject = who/what the sentence is about. Controls verb agreement. Usually a noun/pronoun before the verb.
Diagnostic: ask "who or what [verb]s?" The answer is the subject. The list of items is wrong — what is wrong? The list. That's your subject.
B2 | Upper Intermediate
B2 vs C1: B2 means effective communication on complex topics with some effort. C1 means effortless fluency with precise register control. If you can argue a point but still reach for words and make structural slips under pressure, you're B2.
B2 is the upper-intermediate CEFR level: mixed conditionals, complex passives, reported speech with backshift, participle clauses, and sustained written argument.
Diagnostic: does your writing read as "competent non-native" or "could be native"? The former → B2. The latter → C1.
Hard
Hard vs Medium: Medium tests one rule with realistic distractors. Hard tests interacting rules, edge cases, or context-dependent answers where multiple options seem correct until you think deeply. If you're scoring 80%+ on Medium, try Hard to find your real gaps.
The Hard tag filters for B2+ challenges with layered difficulty: rule interactions, subtle distractors, and contexts that demand genuine grammatical reasoning.
Diagnostic: if Hard questions feel impossible, drop to Medium and master the individual rules first. Hard assumes you already know each rule — it tests whether you can apply them together.