🧠 TOEIC Trap: Until vs By

You thought you nailed it.

The sentence said, “Please finish the task ___ Friday.”
You saw “Friday,” picked “until” — and moved on.

But then… ❌

Another careless TOEIC trap.
Because “until” and “by” both talk about time — but they do very different things. And under pressure, most learners don’t stop to think which one actually fits.

Let’s fix that. Forever.

🎯 Trap Explained

This trap is all about endpoint vs deadline.

  • Until means something continues up to a point in time.

  • By means something is finished before or at a point in time.

TOEIC loves this trap because:

  • The options both seem fine at a glance.

  • “Until” feels more polite or soft — so many learners choose it by instinct.

  • The difference is logic, not vocabulary.

✅ “Until” means the thing keeps going until the time mentioned.

I will wait until 6 PM.
(= I will wait the whole time, up to 6 PM.)

✅ “By” means the thing is done any time before or at that time.

Please finish the report by Friday.
(= The report must be done before Friday ends.)

🧠 Here’s how to break this trap on the test:

  • If the sentence is about a deadline or goal → ✅ use by

  • If the sentence is about something that continues (like waiting, staying, raining) → ✅ use until

🧪 Coached TOEIC Questions

❓1. The manager asked us to submit the form ___ Friday.
(A) until
(B) by
(C) during
(D) after
✅ Correct: B

➡ “Submit” = deadline. Use by.
Until would mean “we keep submitting” — makes no sense.

❓2. She stayed at the office ___ midnight.
(A) until
(B) by
(C) on
(D) of
✅ Correct: A

➡ “Stayed” = continued action.
Until fits. By would mean she left before midnight — different meaning.

❓3. We must complete the testing phase ___ next Tuesday.
(A) until
(B) by
(C) at
(D) to
✅ Correct: B

➡ “Complete” = deadline → ✅ by
Many learners choose until, thinking it sounds more formal — trap!

❓4. I’ll be here ___ 5 PM if you have any questions.
(A) by
(B) until
(C) for
(D) since
✅ Correct: B

➡ “Be here” = continuous action → ✅ until

📝 Practice Test (No Answers)

❓1. The team needs to finish the update ___ tomorrow afternoon.
(A) until
(B) by
(C) for
(D) to

❓2. She will be unavailable ___ Thursday due to meetings.
(A) by
(B) until
(C) at
(D) from

❓3. Please complete the registration process ___ Monday at 10 AM.
(A) by
(B) until
(C) during
(D) after

❓4. I’ll stay here ___ the technician arrives.
(A) until
(B) by
(C) on
(D) since

✅ Answer Key + Mini-Coaching

  1. ✅ B → “Finish” = deadline → use by

  2. ✅ B → “Unavailable” = continues until Thursday

  3. ✅ A → “Complete” = deadline → use by

  4. ✅ A → “Stay” = action continues → use until

🔁 Final Coaching

Don’t trust how “until” feels — it sounds polite but often kills your score.

  • Use by for anything with a deadline.

  • Use until for something that continues.

🧠 Just ask: “Is this something that finishes before the time?”
If yes → by.
If no → until.

Next time TOEIC throws this at you — you’ll nail it without blinking.

FAQ (English) — Until vs By (No numbering, UTF-8 clean, formatted for SEO + chatbot) What is the difference between “until” and “by” in TOEIC questions “Until” means something continues up to a point in time. “By” means something is finished before or at that time. When should I use “by” instead of “until” in TOEIC grammar Use “by” when the sentence is about a deadline or goal — something that must be completed before or at a specific time. Why is “until” the wrong choice in deadline questions “Until” suggests ongoing action. For deadlines, you need “by” to show completion. How do I know if TOEIC wants “until” or “by” Ask: is the action continuing (use “until”) or finishing (use “by”)? That’s the key test. Is “by” used for future deadlines on TOEIC Yes. “By” is the standard preposition to mark future deadlines in TOEIC questions. Does “until” mean the same as “before” No. “Until” shows something continues up to a time. “Before” and “by” show when something is done. What does “by Friday” really mean on TOEIC It means the action should be completed any time before or on Friday — not after. Can “until” be used in TOEIC Part 5 questions Yes, but only when the verb shows a continuous action like “wait,” “stay,” or “work.” Is “until” ever correct in TOEIC deadline questions Rarely. “Until” only fits if the sentence is about continuing, not finishing. What is the grammar logic behind “until” and “by” “Until” = continuous action. “By” = finished action. TOEIC tests this subtle difference often. What kind of verbs follow “by” in TOEIC traps Verbs like “complete,” “submit,” “finish,” “respond,” or “send” often go with “by” in deadlines. How does TOEIC test time prepositions like “by” and “until” TOEIC puts both as answer choices and hides the trap in the logic of the verb. Does “stay until” mean the same as “stay by” No. “Stay until” is correct. “Stay by” is incorrect and unnatural. Can I use “by” when something continues up to a time No. Use “until” when describing something that keeps going up to a certain point. Why do I keep getting “by” vs “until” questions wrong Most people follow feeling, not logic. These questions test meaning, not memory. What is the difference between “stay until” and “leave by” “Stay until” means you are present up to that time. “Leave by” means you are gone before or at that time. Are “until” and “by” tested in TOEIC Part 6 fill-in-the-blank Yes. TOEIC often uses short time-based sentences to test this difference under time pressure. What’s the trick for choosing between “until” and “by” Check if the sentence is about continuing (until) or completing (by). That’s the only thing that matters. How can I practice the “until” vs “by” question type Review real TOEIC-style questions where the action verb tells you the right preposition. Which one is correct: submit until Friday or submit by Friday “Submit by Friday” is correct. “Submit until Friday” is incorrect because “submit” is a completed action.