The correct answers are: The hacker claimed that she could bypass the firewall, but it would trigger an alarm. The hacker claimed that she can bypass the firewall, but it will trigger an alarm.
In reported speech, when the original statement is still true or relevant at the time of reporting, backshifting the tenses and modals (changing can to could and will to would) is optional. Both the backshifted and non-backshifted versions are grammatically correct.
"Could have bypassed" and "would have triggered" are perfect modals that completely change the meaning to an unreal, hypothetical past situation.
Indirect speech
- Direct: "I am tired." → Indirect: She said she was tired. (present → past)
- Direct: "I will come." → Indirect: He said he would come. (will → would)
- Direct: "I have finished." → Indirect: She said she had finished. (present perfect → past perfect)
- today → that day; here → there; tomorrow → the next day
Indirect speech reports someone's words without quotation marks. The mechanism: backshift tenses one step into the past, shift pronouns, and adjust time/place expressions.
Rule: if the reporting verb is past (said, told, asked), shift the reported tense back one step. If the reporting verb is present (says), no shift needed.
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).
Verb tense
| Simple | Progressive | Perfect | Perfect Progressive | |
|---|---|---|---|---|
| Past | worked | was working | had worked | had been working |
| Present | work(s) | am working | have worked | have been working |
| Future | will work | will be working | will have worked | will have been working |
Verb tense = time (past/present/future) × aspect (simple/progressive/perfect) = 12 forms. Each slot has a specific job — not just "when" but "how the action relates to its time frame."
Key insight: most learners don't need all 12 at once. Simple covers 80% of communication. Add perfect and progressive as needed.
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.