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Help the stressed head chef complete the kitchen's new rule board by selecting the correct options.
The secret sauce _________________________ in the fridge at all times. Please remember that the fancy gold-rimmed plates _______________________________ in the dishwasher, or they will lose their sparkle!

The secret sauce must be kept in the fridge at all times. Please remember that the fancy gold-rimmed plates should not be washed in the dishwasher, or they will lose their sparkle!

To form the passive voice with a modal verb, use modal + be + past participle.

The sauce doesn't keep itself; it must be kept by someone.

The plates don't wash themselves; they should not be washed by someone.

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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).

Passive voice

  • The meal was cooked by the chef. — passive (action matters)
  • Mistakes were made. — passive, agent hidden (evasive)
  • ✅ Active: The chef cooked the meal. — stronger, clearer
  • The report was being been written. — malformed passive

The passive = be + past participle. Object becomes subject. Use it when the doer is unknown, irrelevant, or obvious. Avoid when it hides responsibility or weakens prose.

Formula: find the active object → make it the subject → use be (matching tense) + past participle → optionally add by + agent.

Negation

  • I don't see anything. — ❌ I don't see nothing. (double negative in standard English)
  • She never goes out.never already negates (no doesn't needed)
  • He doesn't like coffee. — do-support for negation
  • Nobody came. — negative subject (no auxiliary needed)

Negation uses not after an auxiliary/modal, or do-support when there's no auxiliary. One negative per clause in standard English — never, nobody, nothing already negate without adding not.

Rule: one negative element per clause. I don't see anything or I see nothing — never both together in standard English.

Verb

  • walk → walk / walks / walked / walked / walking (5 forms, regular)
  • go → go / goes / went / gone / going (5 forms, irregular)
  • be → am/is/are/was/were/be/being/been (8 forms)
  • can → can / could (modal: only 2 forms, no -s, no -ing)

A verb is the one word class every English sentence requires. Carries tense (when), aspect (duration), mood (attitude), and voice (active/passive). Regular verbs add -ed; ~200 irregular verbs have unpredictable past forms.

Key insight: fix your verbs and most grammar problems disappear. Wrong tense, wrong agreement, wrong form — verb errors account for the majority of grammatical mistakes.

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.

Medium

  • If I were you, I would apologise. — one rule (second conditional), but distractors like was tempt you
  • Answers require active thought, not instant pattern recognition
  • Vocabulary and context are realistic, not artificially simplified
  • Usually tests one rule, but the wrong answers are plausible

Medium marks middle-difficulty challenges: A2B1, one rule tested, but with realistic distractors that require genuine understanding.

Use "Medium" when Easy feels too obvious but Hard feels overwhelming. This is where most productive learning happens — the sweet spot of difficulty.