One of my best friends...
The phrase "one of" must always be followed by a plural noun, because you are singling out one person or thing from a larger group.
...the modern furniture...
"Furniture" is an uncountable noun in English. It never takes an "s" at the end, even when you are talking about multiple chairs, tables, and sofas!
...each of the decorators wants...
The pronoun "each" is singular, so it requires a singular verb ("wants"), even though it is followed by a plural noun phrase ("of the decorators").
Grammatical number
Grammatical number is the singular vs plural distinction marked on nouns, pronouns, and verbs. Most English nouns add -s or -es to form plurals (book → books, box → boxes), but a handful keep older patterns: child → children, foot → feet, mouse → mice, sheep → sheep. Pronouns swap forms entirely (I → we, he → they).
Number governs subject-verb agreement: He goes but They go. Mismatching subject and verb (The team are/is winning) is one of the most common slips in writing — and one that catches the attention of any careful reader.
Subject
The subject is the part of a sentence or clause that tells you who or what the sentence is about. It's typically a noun, pronoun, or noun phrase that comes before the verb and controls the verb's form: She works (singular) vs They work (plural).
The subject isn't always the doer of the action — in passive sentences, it receives the action (The window was broken). English also uses dummy subjects like it and there that hold the subject slot without carrying real meaning (It is raining; There are problems). Spotting the real subject is what makes subject-verb agreement automatic.
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.
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.