The correct answers are What is this bizarre gadget used for? and For what is this bizarre gadget used?
When asking about purpose, we use "What... for?". The most natural and common way to ask this in English is to leave the preposition "for" at the end of the question.
Moving the preposition to the front ("For what is this...") is grammatically correct but sounds quite formal or old-fashioned.
The option missing "for" is incorrect because "used" requires the preposition to indicate purpose. The final option is incorrect because it lacks the necessary subject-verb inversion for a question (it should be "is this", not "this is").
Questions
Questions in English are typically formed by inverting the subject and an auxiliary verb: She can dance → Can she dance?. When there's no auxiliary present, English adds do-support: The milk goes in the fridge → Does the milk go in the fridge?. The same pattern handles wh-questions (Where do you live?) and negative questions (Doesn't he know?).
The trickiest variant is indirect questions — I wonder where he is, not where is he. The inversion drops because the question is embedded inside another clause. Getting this right is one of the bigger jumps from A2 to B1 fluency.
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.
Word Order
Word order is the sequence in which words appear in a sentence. English is fundamentally an SVO language — subject, verb, object (Kate loves Mark). The order of adjectives, adverbs, and modifiers within a noun phrase also follows fixed patterns (a small red wooden box, not a wooden red small box).
In English, word order carries grammatical meaning — change the order and you change the sentence. The dog bit the man and The man bit the dog differ only in word order, but the meaning flips entirely.
English Grammar Basics
The English Grammar Basics tag marks quizzes and explainers covering the foundations of English grammar — nouns, verbs, adjectives, adverbs, prepositions, conjunctions, tenses, voice, mood, and basic sentence structure.
If you're starting out or rebuilding from scratch, this is the tag to follow: every challenge under it is designed to land the core rules without burying you in exceptions. Get the basics solid here and the more advanced topics — conditionals, reported speech, inversion — stop looking like a wall of new rules and start looking like extensions of what you already know.
B1 | Intermediate
B1 is the intermediate level in the CEFR framework — the point where you stop relying on memorised phrases and start handling everyday English independently. At B1 you can describe experiences, explain opinions, and follow most clear standard speech on familiar topics like work, travel, and hobbies.
Grammatically, B1 means combining tenses with precision, building complex sentences, and starting to use passive voice, modal verbs for necessity and possibility, and verb patterns (gerund vs. infinitive). Knowing your level shapes what you study next: pushing too far ahead frustrates you; staying below your level wastes time.
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.