The correct answers are The idea of scaring teenagers who just stare at their phones is exhausting. and There is no advantage in haunting a house with smart lights.
Nouns like idea, advantage, fear, and intention are often followed by specific prepositions. Whenever a verb follows those prepositions, it must be a gerund (-ing).
The incorrect sentences should be: "fear of being recorded" and "intention of leaving".
Noun
A noun is a word that names something — a person, place, thing, idea, action, or quality. Nouns are one of the open word classes in English, alongside verbs, adjectives, and adverbs. They typically appear as the subject or object of a clause, after articles or adjectives, and as the head of a noun phrase.
Recognising nouns reliably is the foundation for nearly every other grammar topic — agreement, articles, plurals, possessives, and prepositions all depend on it. Get this right and the rest of English grammar starts to fall into place.
Preposition
A preposition is a small word that links a noun or noun phrase to other parts of the sentence — usually marking time, place, or relationship: in, on, at, to, from, with, over, under, between, during. The book on the table, We met at noon, She lives in Berlin.
Prepositions are deceptively small. Their meaning shifts dramatically by collocation (depend on, good at, afraid of), and their choice rarely translates directly between languages. Picking the right preposition is one of the trickiest, most idiomatic-sounding parts of English.
Gerund
A gerund is the -ing form of a verb used as a noun — swimming, reading, being late. It can sit in any position a noun can: as the subject (Swimming is fun), as the object of a verb (I enjoy swimming), or as the complement of a preposition (She's good at swimming).
Gerunds matter because dozens of common English verbs and almost every preposition force you into the -ing form. Pick the wrong shape — I enjoy to swim, good at to swim — and the sentence sounds clearly off to a native speaker. Knowing which contexts demand a gerund (vs. an infinitive) is what makes verb patterns click.
Collocations
Collocations are combinations of words that habitually occur together in a fixed order — make a decision (not do a decision), strong coffee (not powerful coffee), heavy rain (not thick rain). The grammar would allow either pairing, but native speakers consistently pick one and reject the other. Common patterns include verb + noun, adjective + noun, adverb + adjective, and adverb + verb.
Learning vocabulary as collocations rather than isolated words is the single fastest way to sound natural in English. It's the difference between I made a big mistake and I did a big mistake — small, but immediately noticeable.
B1 | Intermediate
B1 is the intermediate level in the CEFR framework — the point where you stop relying on memorised phrases and start handling everyday English independently. At B1 you can describe experiences, explain opinions, and follow most clear standard speech on familiar topics like work, travel, and hobbies.
Grammatically, B1 means combining tenses with precision, building complex sentences, and starting to use passive voice, modal verbs for necessity and possibility, and verb patterns (gerund vs. infinitive). Knowing your level shapes what you study next: pushing too far ahead frustrates you; staying below your level wastes time.
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.