Yesterday, Since, By Friday: TOEIC Time Words That Change the Verb

The stem on your screen looks innocent. Since the new logistics system launched in 2019, our regional warehouses ___ shipping times by nearly forty percent. The four options are reduce, reduced, have reduced, and will reduce. The verb meaning is obvious. The tense is the question. And the tense, in this exact sentence, is already decided — not by you, not by your instinct, but by one tiny word four words from the start.

Since.

That single word locks the main verb into present perfect. Have reduced is the answer. You did not even need to read the rest of the sentence carefully.

This is the most underused speed trick on the TOEIC reading section: a huge family of items secretly tells you the tense before you ever look at the options. The signal is a time expression. Learn the signals and you stop solving these items — you start recognizing them.

Where This Shows Up on TOEIC Listening and Reading

Time-word signals are everywhere on the test. They are densest on Part 5: Incomplete Sentences and Part 6: Text Completion, where a single sentence (or a paragraph) hands you a time expression and asks you to pick the verb form that matches. They surface in Part 7: Reading Comprehension as inference items — the question stem will paraphrase a tense, and the wrong distractors change the tense or the aspect just enough to flip meaning.

On the listening side, Part 3: Conversations and Part 4: Talks test the same logic in the inference items. A speaker says we'll have completed the migration by Friday, and a distractor answer says the migration is already complete. Same time signal, different tense, different meaning. Same trap family.

Here are the four signal families and the verb forms they lock you into.

Trap 1: Since + Present Perfect / For + Present Perfect

Since 2019, our regional warehouses ___ shipping times by nearly forty percent.

A. reduce B. reduced C. have reduced D. will reduce

Since with a year, a date, or a past event signals present perfect. The action started in the past and continues, or has effects that continue, to now. Have reduced.

For with a duration does the same job:

Our regional warehouses have reduced shipping times for the past five years.

Both since and for live in present perfect land. The difference is what they take:

• Since takes a point in time. Since 2019. Since the merger. Since last quarter.
• For takes a duration. For five years. For two decades. For the past quarter.

Common mistake: candidates pick simple past with since. Since 2019 our warehouses reduced shipping times — that sentence does not parse in standard business English. The reduction either happened in 2019 (and then it is In 2019 our warehouses reduced...) or it has been ongoing since 2019 (and then have reduced). Since + simple past is almost always wrong on TOEIC.

A subtler version uses since with a clause:

Since the merger was finalized last year, the combined company has expanded into three new markets.

The clause since the merger was finalized last year contains its own simple-past verb (was finalized) — that is fine, because since governs the main verb of the sentence, not the verb inside the since-clause. The main verb (has expanded) is still present perfect.

Trap 2: Yesterday / Last Week / Ago + Simple Past — Never Present Perfect

This is the mirror image of Trap 1, and it is the trap that catches strong candidates who have been drilled on present perfect.

The new warehouse manager ___ the operations team last Friday.

A. meets B. has met C. met D. is meeting

Last Friday is a specific finished point in the past. Simple past. Met.

The trap is that has met feels like a present-perfect candidate because the action sounds recent and relevant. But the moment the sentence specifies a specific past time point that is finished — yesterday, last week, two days ago, in 2019, on Monday — present perfect is grammatically wrong. Present perfect cannot co-occur with a finished, specified past time.

Compare:

• I have met him. (No specific time. Present perfect fine.)
• I met him yesterday. (Specific past time. Simple past.)
• I have met him yesterday. (Grammatically broken. Present perfect cannot host yesterday.)

The TOEIC distractor pattern on this trap almost always offers you both met and has met, plus two dummies. The presence of yesterday / last week / ago is the decider.

Adjacent traps in the simple-past family:

• In 2019 + simple past.
• On Monday (when Monday refers to a specific past Monday) + simple past.
• Three months ago + simple past.

Trap 3: By + Future Point + Future Perfect

By the end of next quarter, the engineering team ___ the migration to the new platform.

A. completes B. is completing C. will complete D. will have completed

By + future point signals future perfect. The action will be finished before that future point. Will have completed.

The trap is that will complete feels like the natural future-tense answer, and it is even grammatically possible — but the by Friday / by the end of the quarter / by 2030 frame is the canonical home of future perfect for a reason. Will complete says the action happens at some point in the future; will have completed says the action is finished before the future deadline. Business English uses the second meaning constantly, especially in project deadlines.

The decider: if the stem says by + a future time, lean toward will have + past participle. If the stem says next week without by, simple future (will + verb) is more natural.

Compare:

• We will complete the report next week. (Simple future. Some point next week.)
• We will have completed the report by next Friday. (Future perfect. Finished before next Friday.)

A variant that catches candidates is by the time + present simple, which triggers future perfect in the main clause:

By the time the new manager arrives, we ___ the office layout.

A. will reorganize B. will have reorganized C. have reorganized D. reorganize

By the time + present simple (the arrives clause refers to a future event but uses present simple) demands future perfect in the main clause. Will have reorganized.

Trap 4: While / When / As + Past Continuous vs Simple Past

This is the trap family that handles concurrent past events.

While the auditors ___ the financial records, the CFO was preparing the quarterly report.

A. reviewed B. were reviewing C. have reviewed D. will review

While signals a background action that was ongoing at a specific moment in the past. Past continuous. Were reviewing.

The general frame:

• Past continuous for the background action that was ongoing.
• Simple past for the foreground action that interrupted or punctuated it.

While the auditors were reviewing the records, the system crashed.

Were reviewing is the ongoing background. Crashed is the punctuating event.

When and as play similar roles, with some flexibility:

• When often introduces the punctuating event: When the system crashed, the auditors were reviewing the records.
• As often emphasizes simultaneity: As the meeting began, the latecomers were still parking.

The distractor trap on this family almost always offers you both past continuous and simple past for the same blank. The signal word tells you which one.

A close cousin worth flagging in one sentence: prepositions of time interact with this whole family — by Friday versus until Friday versus within Friday (which is wrong, but feels right under time pressure). See our deeper dive on preposition traps for the full pattern.

Wrong / Better / Why

Test-Day Strategy

Time-signal items are the fastest items on the test once you train the reflex. The reflex is simple: hide the verb, read the time word, predict the tense.

Most candidates do the opposite — they read the four options first and try to match them to the rest of the sentence. That order of operations is what eats their per-item budget. The reading section gives you roughly 25 seconds per item on Part 5: Incomplete Sentences, 45 to 60 seconds per blank on Part 6: Text Completion, and an average of about a minute per item across Part 7: Reading Comprehension. Time-signal items in Part 5 should clock in well under twenty seconds if you train the reflex.

Three pacing rules:

1. Scan for the time word first. Since, for, yesterday, ago, by, while, when, as, by the time. If you find one, your tense is decided.
2. Predict the tense before you peek. Then go to the options to confirm. Do not let four shapes blur your prediction.
3. The distractor pair tells you the trap. If the four options are met / have met / will meet / meets, the test is asking simple past or present perfect. The time word in the stem decides.

Quick Check

1. Since the new compliance policy ___ in March, the legal team has reviewed every contract personally.

   • A. takes effect
   • B. took effect
   • C. has taken effect
   • D. will take effect

2. By the end of the fiscal year, the regional offices ___ their migration to the new accounting platform.

   • A. complete
   • B. will complete
   • C. will have completed
   • D. have completed

3. While the IT team ___ the server upgrade last night, the customer service line went offline.

   • A. performed
   • B. was performing
   • C. has performed
   • D. will perform

Answer key
1. B  (the "since"-clause itself takes simple past for the point event; the main clause "has reviewed" is present perfect)
2. C  ("by the end of the fiscal year" = by + future point → future perfect)
3. B  ("while" + ongoing past background → past continuous)

Recap

• Time words decide tense. Find the time word first.
• Since and for lock present perfect.
• Yesterday, last week, ago lock simple past — present perfect cannot co-occur.
• By + future point locks future perfect.
• While, when, as + ongoing past → past continuous as background.

The reflex is built by repetition under timing. Drill time-signal items on ExamRift's TOEIC Part 5 and Part 6 practice until you start predicting the tense before your eye reaches the options at https://examrift.com.