Complete the cybersecurity expert's confident prediction about the system recovery.
As long as the mainframe's processing power remains stable, the corrupted data ________ fully restored by the time the CEO arrives tomorrow morning.
The correct answer is will have been.
We use the future perfect passive (will have been + past participle) to describe an action that will be completed before a specific point in the future (indicated here by the phrase "by the time the CEO arrives tomorrow morning").
"Would have been" is incorrect because the condition is in the present tense ("remains"), not a past hypothetical. "Had been" is past perfect and contradicts the future timeframe, while "is being" refers to an action happening right now.
Future tense
- ✅ I*'ll** help you.* — spontaneous decision (will)
- ✅ I*'m going to** study medicine.* — planned intention
- ✅ I*'m meeting** Sam at six.* — fixed arrangement (present continuous)
- ✅ The train leaves at 8. — scheduled event (present simple)
English has no single future tense — it uses will, be going to, present continuous, and present simple for different shades of future meaning. The choice signals whether you're predicting, planning, arranging, or stating a schedule.
Pattern: spontaneous → will. Planned → going to. Arranged → present continuous. Timetabled → present simple.
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.
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.