40%

The manager keeps a close eye on the employees to ensure they do their work well.

Which of the following statements is true:

To ensure they do their work well is an adverbial clause of purpose

To ensure they do their work well is an adverbial clause of time

To ensure they do their work well is an independent clause

You can also say To ensure they do their work well, the manager keeps a close eye on the employees.

Correct. It gives a reason.
Incorrect. It does not refer to time.
Incorrect. It is a dependent or subordinate clause as you cannot use it by itself.
Correct. You have to insert a comma between the two parts.

Medium B1 | Intermediate Complex sentence Dependent clause Clause Adverb

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Complex sentence

Complex vs compound sentence: a compound sentence links two equal independent clauses with and/but/or. A complex sentence links an independent clause with a subordinate (dependent) clause — one idea is the main point, the other is background.

A complex sentence = independent clause + dependent clause. The dependent clause adds time (when), reason (because), condition (if), or detail (who/which).

Diagnostic: are both halves able to stand alone? Yes → compound. Can only one stand alone? → complex.

Dependent clause

Dependent vs independent clause: an independent clause stands alone as a sentence (I was tired.). A dependent clause has a subject + verb but cannot stand alone (Because I was tired. ❌). The subordinating word is what makes it dependent — remove it and the clause becomes independent.

A dependent clause is introduced by a subordinating conjunction or relative pronoun and functions as an adverb, adjective, or noun inside a larger sentence.

Diagnostic: strip the opening word (because, if, who, which). Does the remainder work as a sentence? Yes → the original was dependent (the subordinator trapped it). No → deeper structural issue.

Clause

Clause vs phrase: a clause has a subject + verb (she runs); a phrase does not (in the morning, running fast). This is the first distinction to make when analysing sentence structure.

A clause is a grammatical unit built around a verb: independent clauses make complete sentences; dependent clauses attach to them as modifiers or complements.

Diagnostic: find the verb. If there's a subject doing or being something → clause. If there's no subject-verb pair → phrase.

Adverb

Adverb vs adjective: adjectives describe things; adverbs describe actions, qualities, or degrees. The mix-up usually happens after action verbs — she sings beautiful (wrong) vs she sings beautifully (right).

An adverb modifies a verb, adjective, or another adverb: incredibly fast, she spoke softly, we go often.

Diagnostic: ask what word is this describing? If it's a verb (an action) → adverb. If it's a noun (a thing) → adjective. Exception: linking verbs (be, seem, taste) take adjectives, not adverbs.

B1 | Intermediate

B1 vs B2: B1 handles standard everyday communication and simple opinions. B2 handles abstract topics, sustained arguments, and nuanced register. If you can chat about your life but struggle to debate an issue or write a formal essay, you're B1.

B1 is the intermediate CEFR level: independent handling of familiar topics, second conditional, basic passive, reported speech, and linking words for cause and contrast.

Diagnostic: can you read a newspaper article on a familiar topic and summarise the argument? Comfortably → B2. Struggle with abstractions → still B1.

Medium

Medium vs Easy: Easy has one obviously correct answer and clearly wrong distractors. Medium has one correct answer but plausible distractors — you need to actually know the rule, not just guess from sound.

The Medium tag filters for A2–B1 challenges with realistic difficulty: one rule per question, plausible alternatives, everyday contexts.

Diagnostic: if you're scoring 90%+ on Easy, move here. If you're below 60% on Medium, go back to Easy for that topic. Target 70–80% accuracy for maximum learning.