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You are reading a top-secret manual for surviving a vampire attack. Select ALL the grammatically correct options to complete this crucial safety rule.
"If you hear a knock at your window at midnight, you ________ keep the door locked!"

The correct answers are must, have to, and have got to.

All three of these options correctly express strong obligation or necessity for the pronoun "you".

Have got to is a slightly more informal (but perfectly correct) way to say have to.

"Must to" is incorrect because modal verbs are followed by a bare infinitive (no "to"). "Has to" is incorrect because it is only used for third-person singular subjects (he/she/it).

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Modal verb

  • She can swim. — ❌ She can to swim. (modal + bare infinitive, no to)
  • You must leave now. — strong obligation
  • It might rain. — possibility (~50%)
  • He should apologise. — advice/recommendation

Modal verbs (can, could, may, might, must, shall, should, will, would) are auxiliaries expressing ability, permission, possibility, obligation, or speculation. Always + bare infinitive. Never inflected (she can, not she cans).

Rule: modals never take to after them, never add -s for third person, and can't combine directly (must can ❌ — use must be able to).

English grammar

  • She is reading. — tense + aspect (present progressive)
  • The cat sat on the mat. — word order + articles
  • He gave her a book. — case + sentence structure
  • Does she know? — auxiliary for question formation

Every one of these involves English grammar — the rule system that turns words into precise meaning. It covers parts of speech, sentence structure, tenses, agreement, word order, and punctuation.

Grammar isn't about memorising rules — it's about understanding why one word order works and another doesn't.

English Grammar Basics

  • She is a teacher. — verb be + noun complement
  • He runs every day. — present simple, third-person -s
  • They don't like coffee. — negation with do-support
  • I have two cats. — possession, countable noun, no article before plurals

These sentences demonstrate English Grammar Basics — the foundational patterns every other topic builds on: parts of speech, basic tenses, articles, and simple sentence structure.

If you can identify the verb, the subject, and count the noun correctly, you've nailed the basics that make everything else click.

Humor

  • "I before E, except after C" — weird, right? — playful self-contradiction
  • Grammar joke: A panda eats, shoots, and leaves. — comma changes everything
  • Silly contexts make rules memorable: the sillier the sentence, the harder it is to forget
  • Entertainment is a learning strategy, not a distraction

Humor marks practice material that's deliberately entertaining. The grammar is real; the packaging is playful. Designed to boost engagement and make rules stick through association.

Why it works: memory anchors to emotion. A funny example of comma misuse is remembered longer than a dry rule statement.

B1 | Intermediate

  • If I had more time, I would travel more. — second conditional
  • The bridge was built in 1920. — passive voice
  • She said she was tired. — reported speech with backshift
  • Although it rained, we enjoyed the trip. — complex sentence with concession

These are B1 patterns — the CEFR intermediate level. At B1 you link ideas, use passive voice, handle reported speech, and manage second conditional — enough for travel, work basics, and everyday independence.

Marker: if you can explain why something happened and follow a news story, you're B1.

Easy

  • She is a teacher. — one verb form, one rule
  • I have two cats. — basic possession, short sentence
  • He doesn't like coffee. — simple negation with do-support
  • Only one answer is clearly correct; distractors are obviously wrong.

Easy marks beginner-level challenges: A1–early A2, one rule at a time, everyday vocabulary, no trick questions.

Use "Easy" when you want to build confidence on a specific rule without interference from other grammar or tricky contexts.