Your taskFill in the gap in each sentence with the correct word or phrase.had takenwill have finishedhas been investigatinghad been drivingwill be presentinghad been leakedintroducedhave been workinghad sentwill have startedhave announcedhad been cryingwill be havinghas been readinghad hoped0 / 15 answeredYour score0 / 150%Keep practising! Focus on the explanations below.1By the time the rescue team arrived, the survivors shelter in an abandoned building.Correct answer: had taken▸ Why?Past perfect (had + past participle) for an action completed before another past event. "By the time + past simple" is a reliable signal: the survivors found shelter before the team arrived.2If everything goes to plan, they the construction by the end of March.Correct answer: will have finished▸ Why?Future perfect (will have + past participle) for an action that will be completed before a future deadline. "By the end of March" is the key signal.3She this software bug for three days and still hasn't found the cause.Correct answer: has been investigating▸ Why?Present perfect continuous (has/have been + -ing) for an activity that started in the past, is still ongoing, and whose duration is emphasised. "For three days" + "still" confirms the action is not finished.4He for nearly eight hours when he finally pulled into a service station.Correct answer: had been driving▸ Why?Past perfect continuous (had been + -ing) for a continuous activity that had been in progress up to a past moment. "For eight hours" emphasises unbroken duration before the past event.5This time next week, we our findings to the board of directors.Correct answer: will be presenting▸ Why?Future continuous (will be + -ing) for an activity that will be in progress at a specific future moment. "This time next week" signals a point in the future when the action is underway.6The confidential report before the minister made her public statement.Correct answer: had been leaked▸ Why?Past perfect passive (had been + past participle) when the subject receives the action and it was completed before another past event. The focus is on the report (not who leaked it), so passive is required.7The government a package of emergency economic measures last autumn.Correct answer: introduced▸ Why?Past simple for a completed action at a specific past time. "Last autumn" is a fixed past time reference — it prevents the use of present perfect, which requires a connection to the present.8The team looks exhausted — they around the clock to meet the deadline.Correct answer: have been working▸ Why?Present perfect continuous for a sustained recent activity whose effects are visible now ("looks exhausted"). The continuous form emphasises the unbroken effort leading up to the present moment.9She confirmed that she the invoice before the system crashed.Correct answer: had sent▸ Why?Past perfect in reported/narrative context for an action that was completed before another past event ("the system crashed"). Both "had sent" and "had already sent" are acceptable; "already" adds emphasis.10By the time you arrive at the venue, the opening ceremony .Correct answer: will have started▸ Why?Future perfect (will have + past participle) for an action that will be completed before a future moment. "By the time you arrive" defines the deadline — the ceremony will be over before then.11The authorities that the river water is no longer safe to drink.Correct answer: have announced▸ Why?Present perfect for a recent event whose result is relevant now (the water is currently unsafe). No specific past time is given, which rules out past simple. Present simple "announce" would describe a habit, not a one-off event.12Her eyes were red because she for a long time.Correct answer: had been crying▸ Why?Past perfect continuous for a continuous activity that was in progress up to a past moment and explains a visible past state. "For a long time" emphasises the duration — use continuous, not simple past perfect.13Don't call between noon and two — the delegates lunch then.Correct answer: will be having▸ Why?Future continuous (will be + -ing) for an activity that will be in progress during a specific future period. "Then" refers to an ongoing moment, not a single completed action.14He the same novel for three months and is still only halfway through.Correct answer: has been reading▸ Why?Present perfect continuous for an activity that started in the past and is still ongoing. "For three months" + "still only halfway" makes clear the action is incomplete. "Has read" (simple) would imply he finished it.15The organisers to attract ten thousand visitors, but the event had to be cancelled.Correct answer: had hoped▸ Why?Past perfect with "hope/plan/intend/expect" expresses an unrealised past intention — they hoped for something that did not happen. "Hoped" (past simple) is also grammatically possible but past perfect makes the contrast with "had to be cancelled" more explicit.Check AnswersPlease answer at least one question first.Found an error in this exercise? Let us know.