The correct answers are should see and have called.
"If you should see..." is a formal way to express a possible future event (first conditional with inversion). "Have called" matches the present perfect tense for a recent action.
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.
Subjunctive mood
- ✅ If I were you… — past subjunctive (not was)
- ✅ I suggest that he go. — present subjunctive (not goes)
- ✅ It's important that she be present. — present subjunctive
- ❌ If I was you… — common in speech, avoided in formal writing
The subjunctive uses bare-infinitive forms (go, be) after verbs of demand/suggestion, and were (not was) in unreal/hypothetical conditions. Two contexts: that-clauses (I insist that he leave) and if-clauses (If she were here).
Rule: after suggest/recommend/demand/insist that… → use base form. In if + unreal condition → use were for all persons.
Conditional sentence
- ✅ If you heat ice, it melts. — zero conditional (always true)
- ✅ If it rains, I*'ll** take an umbrella.* — first conditional (real future)
- ✅ If I had wings, I would fly. — second conditional (unreal present)
- ✅ If I had left earlier, I would have caught the train. — third conditional (unreal past)
Conditional sentences pair an if-clause with a consequence. Five patterns (zero through mixed) each combine specific tenses to express different levels of reality and time.
Pattern: the tense in the if-clause is always one step "back" from what you'd expect — past for present hypotheticals, past perfect for past hypotheticals.
B2 | Upper Intermediate
- ✅ If I had studied harder, I would have passed. — third conditional
- ✅ The report is being reviewed by the committee. — passive progressive
- ✅ Having finished the exam, she left. — participle clause
- ✅ He denied having taken the money. — complex verb pattern
These are B2 patterns — the CEFR upper-intermediate level. At B2 you handle mixed conditionals, all passive forms, participle clauses, and can argue a point clearly. This is the level most universities and employers require.
Marker: if you can write a structured essay and debate an abstract topic, you're B2.
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.