"As a junior chrononaut, you mustn't interact with your past self under any circumstances, as this will destroy the universe. On the bright side, you don't have to memorize every historical date, since your temporal tablet has a built-in search engine."
Mustn't means "do not do this." Interacting with your past self is forbidden because it has disastrous consequences.
Don't have to means "it is not required." You aren't forced to memorize the dates because the tablet does the work for you.
Modal verb
A modal verb is a special class of auxiliary — can, could, may, might, must, shall, should, will, would — that adds shades of meaning around possibility, ability, permission, obligation, or speculation. I can swim (ability), You should rest (advice), It might rain (possibility), You must leave (obligation).
Modals are grammatically peculiar: no -s in the third person (she can, not she cans), no infinitive, no participle, followed by the bare verb (I can swim, never I can to swim). Mastering them is the move from describing facts to expressing how you feel about them — likelihood, necessity, recommendation.
Verb
A verb is a word that expresses an action, a state, or an occurrence — the engine of every English sentence. Most verbs have five forms: base (go), -s form (goes), past tense (went), past participle (gone), and -ing form (going). The verb be is the major exception with eight forms; modal verbs like can and must have fewer.
Verbs carry tense (when), aspect (how it unfolds), mood (the speaker's attitude), and voice (active vs passive). Mastering them is foundational — virtually every other grammar topic depends on getting verbs right.
English grammar
English grammar is the system of rules that govern how meanings are encoded in English — covering everything from word formation to phrase, clause, and sentence structure, up to the patterns that connect sentences in longer texts. It includes parts of speech, tenses, voice, mood, word order, punctuation, and the agreement rules that hold them together.
Grammar isn't a list of arbitrary do's and don'ts — it's the predictable system that lets you say things you've never said before and be understood. Learning it deliberately is the fastest way to move from "I can be understood" to "I can express what I actually mean".
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.
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.
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.