Help Detective Lewis finish her official crime report by dragging the correct words into the blanks.
The suspect whose alibi was completely fake tried to sneak out the back door.
Unfortunately for him, the mysterious informant, from whom the detective received the anonymous tip, had already blocked the exit.
Later, the police searched the abandoned warehouse where the stolen jewels were hidden inside a giant donut box.
The suspect whose alibi was completely fake tried to sneak out the back door.
We use whose to show possession (the alibi belongs to the suspect).
Unfortunately for him, the mysterious informant, from whom the detective received the anonymous tip, had already blocked the exit.
We use whom instead of "who" in formal registers when it is the object of a preposition (like "from").
Later, the police searched the abandoned warehouse where the stolen jewels were hidden inside a giant donut box.
We use the relative adverb where to refer to a physical place or location.
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.
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).
Adverb
If you've ever written she sings beautiful when you meant beautifully, you've hit the most common adverb mistake. The fix sounds small, but it's the kind of detail that signals fluency at a glance — and once you see the pattern, you stop second-guessing it.
An adverb modifies a verb, an adjective, or another adverb, telling you how, when, where, how often, or to what degree: she sings beautifully, unbelievably fast, we go there often. Most form with -ly (quick → quickly), but a stubborn group don't change shape at all: fast, well, hard, late.
Possessive
If you've ever stared at its and it's and not been sure which one belonged in your sentence, you've met English's most-confused possessive. The fix is small but immediate: its (no apostrophe) is the possessive of it; it's (with apostrophe) always means it is or it has. Get this right and you instantly look more careful as a writer.
The possessive form shows ownership in English. Most nouns take 's (Sarah's book); plural nouns ending in s take just an apostrophe (students' essays). Pronouns have irregular possessive determiners (my, your, his, her) and pronouns (mine, yours, his, hers).
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).
B1 | Intermediate
If you can hold a conversation about your weekend, explain why you're late, and follow a short news story without panicking — but still feel lost in fast or technical English — you're probably operating at B1. Knowing this matters: study material at the wrong level either bores you or burns you out, and B1 is the typical target for travel, casual work, and most everyday social English.
B1 is the intermediate level in the CEFR framework, where you handle everyday English independently and start combining ideas with complex sentences, passive voice, and modal verbs.
Difficulty: Medium
If easy questions feel too obvious but hard questions leave you guessing, you're probably ready for Medium — the level where most real learning happens. It pushes just enough to expose the rules you don't quite have yet, without burying you in edge cases. This is where steady fluency is built, one well-aimed challenge at a time.
The Medium difficulty tag marks middle-range challenges — typically A2 to B1. One rule per question, realistic distractors, and contexts that require active thought rather than instant recognition.