Help the time traveler complete his highly unusual excuse report for HR by dragging the correct words into the blanks.
I arrived three centuries late because I accidentally typed the wrong year into the dial.
The HR department is furious with me because of the massive paradox I created yesterday.
I will hide in the cafeteria as the timeline police are currently searching my cubicle.
I arrived three centuries late because I accidentally typed the wrong year into the dial.
You must use the conjunction because when following it with a full clause (subject "I" + verb "typed").
The HR department is furious with me because of the massive paradox I created yesterday.
You must use the preposition because of when following it with a noun phrase ("the massive paradox"). "Since" and "as" require a full clause with a subject and verb.
I will hide in the cafeteria as the timeline police are currently searching my cubicle.
As introduces the adverb clause of reason ("the timeline police are currently searching"). "Due to" would incorrectly require a noun phrase, and "although" would illogically introduce a contrast instead of a reason.
Conjunction
A conjunction is a word that connects other words, phrases, or clauses. English has two main types: coordinating conjunctions join units of equal weight (and, but, or, so, yet, for, nor — the FANBOYS), while subordinating conjunctions introduce dependent clauses (because, although, if, when, while, since, unless).
Conjunctions are how you build compound and complex sentences instead of stacking short ones. The choice of conjunction signals the relationship between the ideas — addition, contrast, cause, condition, time — so picking the right one shapes the whole meaning.
Phrase
In grammar, a phrase is a group of words (sometimes a single word) that functions as a single unit in a sentence — but doesn't include a subject + verb pair the way a clause does. Common types: noun phrase (the old red car), verb phrase (has been running), prepositional phrase (on the table), adjective phrase (incredibly tired), adverb phrase (very quickly).
Phrases are the building blocks between individual words and full clauses. Recognising them helps you see how sentences hold together — and where you can break, expand, or rearrange them without losing meaning.
Clause and sentence
The Clause and sentence tag groups together topics that span both clauses (grammatical units built around a verb) and sentences (one or more clauses making a complete thought). Think conjunctions, subordination, sentence types — anything where the line between clause-level and sentence-level rules blurs.
Browsing here is useful when you're working on connecting ideas: building complex sentences, choosing the right punctuation between clauses, or understanding why some phrases stand alone and others can't.
Preposition
A preposition is a small word that links a noun or noun phrase to other parts of the sentence — usually marking time, place, or relationship: in, on, at, to, from, with, over, under, between, during. The book on the table, We met at noon, She lives in Berlin.
Prepositions are deceptively small. Their meaning shifts dramatically by collocation (depend on, good at, afraid of), and their choice rarely translates directly between languages. Picking the right preposition is one of the trickiest, most idiomatic-sounding parts of English.
Clause
A clause is a grammatical unit built around a verb — typically a subject plus a predicate (She laughed; The manager approved the budget). Clauses come in two types: independent clauses stand alone as complete sentences; dependent clauses need an independent clause to make sense (Because I overslept — incomplete on its own).
Spotting clause boundaries is the foundation of correct punctuation. Once you can see where one clause ends and another begins, comma rules, run-on sentences, and complex sentence structure stop being mysteries.
Humor
The Humor tag marks questions and challenges where the author has tried — subjectively, deliberately — to make the practice itself entertaining. Expect characters, scenarios, and storylines that play with absurdity: zombies, alien tourists, a chef's disaster, a roommate's complaint. The grammar rule is real; the wrapping isn't.
Humor matters because grammar drills are forgettable. Tying a rule to a story your brain wants to keep makes it stick. Filter by Humor when motivation is what you're short on, not study time.
B2 | Upper Intermediate
B2 is the upper-intermediate level in the CEFR framework, sitting between B1 and C1. At B2 you can read editorials, follow most TED talks without subtitles, and hold extended conversations on abstract topics — including topics outside your everyday life.
Grammatically, B2 means flexible control of mixed conditionals, passive voice across tenses, reported speech with proper backshifting, and participle clauses. B2 is the standard target for university entrance exams (IELTS 5.5–6.5, TOEFL 87–109) and most skilled-migration thresholds — knowing whether you're there shapes your study plan.
Difficulty: Medium
The Medium difficulty tag marks questions and challenges in the middle of the difficulty range — typically suitable for A2 to B1 learners. Expect a single rule with realistic distractors, longer sentences, and contexts where you have to think before answering rather than reading off the obvious choice.
Filter by Medium when you're past the absolute basics and ready to consolidate. It's the level where most lasting progress happens — easy enough that you can finish without exhausting concentration, hard enough that getting it right means you've actually understood.