50%
Select the correct sentence.
  1. Less and the least are used with adjectives and adverbs in the same way as more and the most. Less indicates a lower degree and least indicates the lowest degree. It's not possible to say the less complicate; we need to use the superlative here: the least complicated.
  2. Less and the least are used with adjectives and adverbs in the same way as more and the most. Less indicates a lower degree and least indicates the lowest degree. However, complication is a noun, not an adjective, and therefore we can't use it here.
  3. Less and the least are used with adjectives and adverbs in the same way as more and the most. Less indicates a lower degree and least indicates the lowest degree. The four-syllable regular adjective complicated shouldn't change its form. We need to use the superlative here: the least complicated.
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Comparative and superlative

Comparative vs superlative: comparative compares two things (taller than); superlative picks the extreme from three or more (the tallest). If there are only two options, never use the superlative — the taller of the two, not the tallest of the two.

Comparatives use -er or more; superlatives use -est or most. Short adjectives take suffixes; longer ones take more/most. A small irregular set (good/better/best) follows no pattern.

Diagnostic: how many items are being compared? Two → comparative. Three+ → superlative. Also: never double up (more better is always wrong).

Adjective

Adjective vs adverb: both describe things, but adjectives attach to nouns while adverbs attach to verbs. A quick answer (adjective → noun) vs answered quickly (adverb → verb).

An adjective modifies a noun or pronoun — telling you what kind, which one, or how many: a red car, something useful, three heavy boxes.

Diagnostic test: if the word describes a thing or person, use the adjective form. If it describes an action, you need the adverb (-ly) form instead.

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.