50%
Help a pompous spaceship captain log his official report about a bizarre alien encounter by choosing the best words for each gap.
Captain's Log, Stardate 4092:
The mysterious neon-pink nebula _________________________ the strange transmission originated smelled strongly of strawberries. Unfortunately, the six-eyed alien ambassador, _________________________ I attempted to negotiate a peace treaty, simply ate my communication device and burped.

The correct answers are from which and with whom.

In official or formal registers, we avoid ending a sentence with a preposition (preposition stranding) by moving the preposition before the relative pronoun.

  • A transmission originates from a place, giving us "from which." ("That" cannot follow a preposition).
  • You negotiate with someone. When referring to a person after a preposition, you must use the objective case "whom," giving us "with whom."
To ChallengesPreviousNext

Relative clause

If you've ever paused over who vs whom vs that vs which — or wondered whether a comma belongs before who — you've hit the relative-clause puzzle. English makes meaning depend on whether the clause is essential information or just extra; one missing comma can flip the meaning of the whole sentence.

A relative clause is a dependent clause modifying a noun, introduced by a relative pronoun (who, whom, whose, which, that) or relative adverb (where, when, why). Restrictive relatives are essential and unmarked; non-restrictive are extra information and set off with commas.

Preposition

If you've ever written I'm interested on you (should be in) or I'm good on football (should be at) — you've hit prepositions' main pitfall. Their choice is mostly idiomatic, not logical, and rarely matches what your native language does. Memorising the right preposition for each common verb and adjective is what stops your speech from sounding subtly off.

A preposition is a small word linking a noun or noun phrase to other parts of the sentence: in, on, at, to, from, with. Marks time, place, manner, or abstract relationships. Choice is largely idiomatic, especially in fixed combinations (depend on, good at, afraid of).

Pronoun

If you've ever paused before who vs whom, its vs it's, or me vs I — you've felt how much weight pronouns carry in English. They're tiny words but they're case-sensitive (I vs me), context-dependent, and one of the few places where everyday English still trips careful speakers. Get the common patterns right and you instantly sound more careful.

A pronoun is a closed class of small words that replace nouns or noun phrases. Types: personal (I, you, he…), demonstrative (this, that), relative (who, which), interrogative (who?, what?), reflexive (myself), and indefinite (everyone, nobody).

Clause

If you've ever been told your sentence is a "run-on" or that you've used a comma where there should be a semicolon — you've hit the limits of writing without seeing clauses. Get this concept solid and most punctuation problems quietly disappear: you can finally tell a complete thought from a fragment without guessing.

A clause is a grammatical unit built around a verb, usually with a subject and a predicate. Independent clauses stand alone (I missed the bus); dependent clauses can't (Because I overslept). Combine them and you build complex sentences.

Word Order

If your first language has flexible word order — Russian, Latin, German, Japanese — English can feel rigid. You can't just rearrange words for emphasis the way you would at home; the grammar tracks position, not just inflection. Get the order wrong and the sentence either changes meaning or stops making sense.

Word order is the sequence of words in a sentence. English is an SVO language — subject, verb, object. The order of adjectives and modifiers in a noun phrase also follows fixed patterns. Get this right and your English instantly sounds more natural.

B2 | Upper Intermediate

If a university admissions team or visa office has ever asked you for an English test score, B2 is probably the level they had in mind. It's the threshold where your English stops being a constraint and starts being a tool — and the line between B1 and B2 is often the line between "stuck in beginner classes" and "ready to study or work in English."

B2 is the upper-intermediate level in the CEFR framework, demanding flexible control of mixed conditionals, passive voice across tenses, reported speech with backshifting, and participle clauses.

Difficulty: Hard

If easy and medium questions are clicking but you still feel exposed in real conversation or formal writing, you've outgrown the basics. Hard material is where the gaps you didn't know you had show up: the distractor that "sounds right", the rule that interacts with another rule, the case where context changes the answer. It's where genuine fluency is built.

The Hard difficulty tag marks upper-intermediate to advanced challenges — typically B2 and above. Interacting rules, edge cases, plausible distractors, and contexts that require genuine understanding rather than surface pattern-matching.