Cycling through a problem set means solving every question on the first pass to surface your mistakes, then repeating only the questions you got wrong until none are left. This article is for anyone who has been handed a problem set and told to "work through it." It uses passed.jp's English problem set as the example and lays out a cycle that actually sticks, step by step, with the reasoning behind each step.

Hand someone a problem set, and nobody tells them how to cycle through it so it moves the needle. Most people solve it in order, check the answer when they get one wrong, and move on. Then they do one pass and call it done.

Here's the conclusion up front: that doesn't work. Whether a problem set pays off isn't decided on the first pass. It's decided by how you carry the questions you got wrong into the second and third pass.

The steps are the main event. Each one comes with a one-line "why it works." I'll touch on the philosophy briefly at the end.

How should you do the first pass? Solve everything, without timing yourself

On the first pass, solve every grade-level question without timing yourself. Don't worry about how many you get right. If anything, go in with the mindset of solving in order to get things wrong.

  1. Solve the grade-level drills in full, without a timer. passed.jp's English problem set has grade-level drills (junior-high years one through three, plus vocabulary). You work through them in batches of 5, 10, or 15 questions. Go through these without timing yourself, and answer with whatever comes to mind. → Why it works: The goal of the first pass isn't to score points. It's to surface exactly where you don't understand something yet. Time yourself, or worry about your score, and you'll unconsciously start picking questions you can solve, which hides your real weak spots.

  2. Guess on the questions you don't know. There's no need to stop and agonize. If you don't know, pick something, anything, and move on. → Why it works: Going deliberately rough and hitting everything is what brings every weak spot to the surface. The mistakes that show up here are exactly what the rest of your study will target.

  3. Ignore the score and percentage at the end. When you finish, you'll see a score and a percentage correct. The number itself doesn't matter. → Why it works: What matters isn't the score but the record of where you went wrong, which comes next. That record, not the score, is what decides your second pass.

Why shouldn't you skim past the questions you missed?

Because the moment you check your answers is where the real gap opens up. Memorizing the correct answer and understanding why you got it wrong are two different jobs, and if you skip the second one, you'll repeat the same mistake on the second pass.

  1. For every wrong answer, read the explanation all the way to the error pattern. For a question you got wrong, you see your answer and the correct one, plus an explanation of why you'd pick that wrong choice in the first place: the pattern behind the mistake. For example, picking the be-verb for "I" when the subject is actually third-person singular. It names the mistake people tend to make. → Why it works: If you only look at the answer and memorize "the be-verb is is," you'll make the same misjudgment the next time a similar sentence shows up. Only once you've put into words how you reasoned your way into the wrong answer do you stop falling into the same trap. Skip the explanations and move on, and you'll repeat the exact same mistakes on the second pass.

  2. Right after the first pass, scan the list view. Once you've finished every question, a list view lets you line up your answers against the correct ones. From there, you can go back into the explanation for any single question. → Why it works: That one extra step changes how efficient your second pass turns out to be.

What should you redo on the second pass? Only the questions you got wrong

On the second pass, redo only the questions you missed on the first. There's no need to solve everything again.

  1. Narrow the target to the first-pass mistakes. A question you got right on the first pass is one you already understand, at least for now. Spending more time there is digging in a spot with no ground left to gain. → Why it works: Limited time should go only to what you don't understand yet. The whole point of solving everything on the first pass was to build this narrowed-down list.

  2. If you miss it again, read the explanation again. You might get some of them wrong again on the second pass. That's not a failure. It's the expected response. If reading an explanation once were enough to lock something in, nobody would need a review step at all. → Why it works: This time you think through why you picked the same wrong answer even though you'd just read the explanation, and that's when the actual pattern of your mistake starts to show itself.

How long should you keep going after the third pass? Until nothing is left

The third pass works the same way. Narrow down to only the questions you still got wrong on the second pass, and keep going until the count hits zero.

  1. Solve only what you still missed on the second pass. Every time you repeat this, the number of target questions shrinks. If you missed ten on the first pass, a healthy pattern is five left on the second, two on the third, and so on. → Why it works: Given the same amount of time, concentrating it on what you still can't solve gets you further. There's no need to dutifully redo every question each time.

  2. If a unit isn't shrinking, step away from memorizing answers and go back to its basics. Sometimes the same questions keep coming back no matter how many times you cycle through them. When that happens, go back to the basics of that unit. → Why it works: A count that won't shrink is a sign that your understanding of that unit itself is shallow.

What should you do when your weak spots cluster in one unit?

Use the topic pages built around individual grammar points, and hit only your weak unit, all at once.

After a few passes through the grade-level drills, a pattern often shows up: "I keep missing the passive voice," or "present perfect is the one I can't get." That's when the topic pages come in.

  1. Narrow in on the page for your weak unit and repeat only that. passed.jp's English problem set has a substantial set of questions organized by unit: the be-verb, general verbs, present progressive, questions, past tense, auxiliary verbs, future tense, there is/are, conjunctions, infinitives and gerunds, comparison, the passive voice, present perfect, relative pronouns, participial constructions, indirect questions, relative adverbs, idioms, and vocabulary. It's a faster format: tap an answer and see it color-coded as right or wrong on the spot. There's no need to go question by question in order. → Why it works: You can take the weak unit you found through the grade-level drills and hit it hard, all at once. The more clearly your weak spots cluster around a specific grammar point, the more this changes your results.

  2. Use the vocabulary and idiom pages to build your word bank. Among the units, vocabulary and idioms have an especially large number of questions. → Why it works: With that many questions, you can use them directly to build up your vocabulary.

When should you use the Impact department? As the final push

After you've seriously worked through a few cycles, as a change of pace and a final push for retention. It isn't a substitute for steady repetition.

passed.jp's English problem set has a special section called "Impossible English." It uses outlandish, real-event-based sentences, like a quirky scam-email mistranslation or a social-media news item, to carve grammar into memory. The World Cup 2026 special questions work the same way, drawing on current events.

→ Why it works: The hook of "oh, that's the same shape as that weird sentence" sticks around longer than a flat example sentence ever will. Put it on top of the foundation you've built through plain, repeated cycling, as a push that makes memory last.

What should you not do when cycling a problem set?

What they all have in common is repeating the same work mindlessly. Flip the steps above, and you get these five.

  • ① Time yourself and worry about your score on the first pass. You start picking questions you can solve, and your real weak spots stay hidden.

  • ② Skim past the explanation for a wrong answer and move on. Memorize only the correct answer, and you'll make the same misjudgment the next time a similar sentence shows up. The first-pass mistake repeats on the second pass.

  • ③ Redo every question on the second pass and beyond. Spending time on questions you already got right is digging where there's no ground left to gain.

  • ④ Keep memorizing answers for a unit that isn't shrinking. A count that won't shrink is a sign that your understanding of that unit itself is shallow. Step away from memorizing the answers and go back to the basics of that unit.

  • ⑤ Use the Impact department instead of repetition. It's a final push on top of the foundation built by plain cycling, not a replacement for it.

The cycle, summarized

Boiled down, here's what to do.

  1. First pass: solve every grade-level question without timing yourself. The goal is to surface your weak spots.
  2. For anything you get wrong, read the explanation all the way through to why you picked that specific wrong answer, not just what the right one is.
  3. Second pass: narrow down to only the questions you missed, and solve again.
  4. Third pass and beyond: keep narrowing to whatever you still miss, until nothing's left.
  5. Once a weak unit becomes clear, hit that unit specifically using the topic-based pages.
  6. Use the Impact department and current-events questions as a change of pace and a final push for retention.

Surface everything on the first pass, then spend every pass after that only on what's left once you've stripped the rest away. Do just this, and the same problem set moves you far further than it otherwise would.

FAQ

How many passes should I do?

Don't decide by a fixed number. Carry only the questions you got wrong into the next pass, and keep going until none are left. If you missed ten on the first pass, a healthy pattern is five on the second and two on the third.

Why shouldn't I time myself on the first pass?

Because worrying about time or your score makes you unconsciously pick questions you can solve. The goal of the first pass is surfacing weak spots, not scoring points, so go rough and hit everything.

I got the same question wrong again on the second pass. What now?

That's the expected response. Read the explanation again, and think through why you picked the same wrong answer even though you'd just read it. That's how the pattern of your mistake shows itself.

The questions I miss aren't shrinking no matter how many passes I do.

That's a sign your understanding of that unit itself is shallow. Step away from memorizing the answers and go back to the basics of that unit. If your weak spots cluster around a specific grammar point, use the topic page and hit only that unit.

Can I study with just the Impact department?

It isn't a substitute for steady repetition. Use it as a final push for making memory last, on top of the foundation you've built through plain cycling.

One last thing. Studying, English or otherwise, doesn't end the moment you pass. When you're on the other side of passing and someone actually needs to rely on what you know, whether it holds up comes down to this unglamorous cycle, repeated. Chipping away one wrong answer at a time, not a flashy shortcut, turns out to be the fastest way there in the end.