Help the HR manager complete her humorous notes on the annual office bake-off. Drag the correct auxiliary verbs to complete the sentences, using ellipsis to avoid repeating the main verbs.
Sarah claimed she would bake a three-tier masterpiece, but she ultimately didn't.
Michael's pie was completely devoured by the marketing team, and David's cookies were too.
The judges could have awarded a tie, and frankly they should have, given how close the final scores were.
Sarah claimed she would bake a three-tier masterpiece, but she ultimately didn't.
Didn't correctly stands in for the elided verb phrase "bake a three-tier masterpiece." We use the past simple auxiliary because the action refers to a completed reality in the past, contrasting with her past claim ("would bake").
Michael's pie was completely devoured by the marketing team, and David's cookies were too.
When the first clause is in the passive voice ("was devoured"), the coordinated clause must also use the "to be" auxiliary. Since "cookies" is plural, we use were.
The judges could have awarded a tie, and frankly they should have, given how close the final scores were.
To elide a past modal phrase ("awarded a tie"), we must retain the modal and the perfect auxiliary "have." "Should" alone would incorrectly imply a present or future obligation, and "ought" requires the particle "to" (ought to have).
Auxiliary verb
- ✅ Do you know? — ❌ Know you? (English requires do-support for questions)
- ✅ She has finished. — ❌ She finished has. (auxiliary before main verb)
- ✅ They are leaving. — ❌ They leaving. (progressive needs be)
- ✅ He doesn't smoke. — ❌ He smokes not. (negation needs do)
Auxiliary verbs (be, have, do, and the modals) combine with main verbs to build questions, negatives, tenses, aspects, and passive voice.
Pattern: if you need to ask a question, negate, or stack tense/aspect — you need an auxiliary. The main verb carries meaning; the auxiliary carries grammar.
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.
Coordination
- ✅ I like reading, swimming, and cooking. — parallel verb forms
- ❌ I like reading, swim, and to cook. — broken parallelism
- ✅ She is smart and hardworking. — adjective + adjective
- ❌ She is smart and works hard. — adjective + clause (mismatched)
Coordination links grammatically equal elements with a coordinating conjunction (and, or, but). The golden rule: all items in a coordinated structure must be the same form.
Test: replace the conjunction with a bullet list. Do all items have the same grammatical shape? If not, you have a parallelism error.
Perfect tense
- ✅ I have lived here for ten years. — present perfect (started past, still true)
- ❌ I live here for ten years. — wrong (simple present can't bridge past→now)
- ✅ She had finished before I arrived. — past perfect (earlier past)
- ✅ They will have left by noon. — future perfect (completed before future point)
The perfect = have + past participle. Connects an action to a reference point in time. Present perfect bridges past→now. Past perfect marks "earlier past." Future perfect marks "done before a future deadline."
Rule: if the action started in the past and is still relevant now → present perfect (have done). If two past events and you need the earlier one → past perfect (had done).
C1 | Advanced
- ✅ Not only did she finish early, but she also helped others. — inversion for emphasis
- ✅ It is the process that matters, not the result. — cleft sentence
- ✅ I insist that he be present. — formal subjunctive
- ✅ Were I to disagree, I would say so. — inverted conditional
These are C1 structures — the CEFR advanced level. At C1 you control inversion, cleft sentences, subjunctive forms, and register-switching fluently across formal and informal contexts.
Marker: if you can restructure a sentence for rhetorical effect without hesitation, you're C1.
Hard
- Had she not intervened, the situation would have escalated. — inverted conditional
- All distractors are grammatically plausible in other contexts
- Multiple rules interact (e.g., tense + aspect + modality)
- Context determines the answer — no single "rule" is enough
Hard marks upper-intermediate to advanced challenges: B2+, interacting rules, edge cases, plausible distractors, and contexts where pattern-matching fails.
Use "Hard" when Easy/Medium feel trivial and you want to test whether you actually understand a rule versus just recognising surface patterns.