Help the veterinarian complete her observational notes on a very cunning feline by choosing the correct word.
_____, Sir Paws-a-Lot was fast asleep on the radiator, but the slight twitch of his ear whenever the tuna can opened suggested a brilliant deception.
The correct answer is Ostensibly.
"Ostensibly" is a sentence adverb used to indicate that something appears or is claimed to be true, but very possibly is not. Here, it modifies the entire first clause, perfectly setting up the contrast with the cat's true, sneaky wakefulness.
"Consequently" indicates a result, "invariably" means always, and "expressly" means explicitly—none of which fit the context of a convincing but fake nap.
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.
Sentence
If your writing has been called "choppy" or "monotonous", the issue is usually sentence variety — not vocabulary. English readers expect a mix of short and long, simple and complex sentences. Even the same content reads completely differently depending on how you stitch the clauses together.
A sentence is the largest grammatical unit, made of one or more clauses. Four structural types: simple (one independent clause), compound (two+ independents joined), complex (independent + dependent), compound-complex (multiple of each). Ends with period, question mark, or exclamation mark.
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.
C1 | Advanced
If you've ever sat through a lecture in English, written a complaint letter, or argued a point in a meeting and come out feeling actually understood — not just tolerated — you've felt what C1 looks like. The level matters because it's where most universities, certifications, and skilled-work environments draw their language line.
C1 is the advanced level in the CEFR framework, demanding fluent and flexible language: inversion for emphasis, mixed and advanced conditionals, formal subjunctive, cleft sentences, and complex nominal phrases — all used appropriately across registers.
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.