// Japanese · Part 7 of 7 · original 2026-10-10 · rewritten and checked on this site 2026-10-12
Japanese notes 7 | Review: 43 common traps, the connection table and the revision log
The final test is not whether you can recite the translations, but whether you can explain “why this form is here.” This part collects the 43 common traps, the connection table and a four-layer check, along with the revision log, the source map and the external checks.
- Beginner course L1–L21 and later class notes
- Original notes, editor’s analysis and revisions are labeled separately
- Japanese examples stay in the original in all three language editions
41 | 43 frequent traps, with their original IDs
Find the error pattern first, then memorize the correct form; an incorrect example is not a blanket ban that still holds outside its context.
Editor’s analysis
Below are all of the source handbook’s 43 items, A01–B43, re-sorted by number to avoid the jumps in reading order (A01, A08, A02) caused by extracting the original two-column layout. This is the original notes’ list of frequent traps; it does not mean a learner will necessarily make all 43 of these mistakes.
The “三枚を買う” item has been narrowed back to the scope of the original example: “を repeated after the object.” Expressions that can only be judged by changing the context are not turned into absolute rules with a red cross alone. The old wording can still be compared on the original page.
| Original ID / topic | Error pattern and correct form | Decision rule |
|---|---|---|
| A01 Style before とき |
× 食べませんとき ○ 食べないとき |
Rule: noun modifiers take the plain form. Original notes |
| A02 Nouns and na-adjectives |
× 30歳なとき／暇のとき ○ 30歳のとき／暇なとき |
Rule: identify the part of speech first. Original notes |
| A03 前に |
× 昨日、寝た前に ○ 昨日、寝る前に |
Rule: 前に always takes the dictionary form. Original notes |
| A04 後で |
× 明日、終わる後で ○ 明日、終わった後で |
Rule: before 後で, use the ta-form to show relative completion. Original notes |
| A05 てから／たから |
× Mixing up the two forms ○ 帰ってから／帰ったから |
Rule: the first marks sequence, the second marks cause. Original notes |
| A06 Tense with たり |
× A た inside 見たり = the whole sentence is past ○ Look at the final する／した |
Rule: the outermost predicate controls the tense. Original notes |
| A07 ことがある |
× 行くこと = past experience ○ 行ったこと = past experience |
Rule: Vる = occasionally; Vた = experience. Original notes |
| A08 Polite form inside a clause |
× 買いました本 ○ 買った本 |
Rule: modifying clauses take the plain form. Original notes |
| A09 Negative of ある |
× あらない ○ ない |
Rule: an irregular change. Original notes |
| A10 Particle after の |
× の is always followed by が ○ The predicate that follows decides は・が・を・に |
Rule: look at the outer case frame. Original notes |
| A11 Inner- and outer-layer particles |
× 友だちを来る ○ 友だちが来るのを待つ |
Rule: が belongs to 来る; を belongs to 待つ. Original notes |
| A12 を and する |
× Fill in する whenever there is a を ○ 本を読む／ご飯を食べる |
Rule: choose the predicate first. Original notes |
| A13 に／で |
× 図書館に本を読む ○ 図書館で本を読む |
Rule: the place where an action happens takes で. Original notes |
| A14 Where an event takes place |
× 学校にコンサートがある ○ 学校でコンサートがある |
Rule: activities and events take で. Original notes |
| A15 旅行 (travel) |
× 旅行へ行く (as the exam’s first choice) ○ 旅行に行く |
Rule: an activity as a purpose takes に. This is the form the original textbook prefers; it does not declare that 旅行へ行く does not exist in any context. Original notes |
| A16 電車 (train) |
× The same particle for every verb ○ に乗る／を降りる／で行く |
Rule: each verb has its own case frame. Original notes |
| A17 Transitive and intransitive verbs |
× 授業を始まる ○ 授業が始まる／授業を始める |
Rule: が for something that happens by itself; を for an action applied to something. Original notes |
| A18 わかる／知る |
× 読み方をわかる ○ 読み方がわかる／を知る |
Rule: the predicates have different case frames. Original notes |
| A19 そう |
× 降るそう = “looks like it will” ○ 降りそう = “looks like it will” / 降るそう = “I hear that” |
Rule: the connecting form decides the meaning. Original notes |
| A20 たまに |
× たまたま = occasionally ○ たまに = occasionally / たまたま = by chance |
Rule: frequency is not the same as chance. Original notes |
| B21 たいてい |
× だいたい = usually ○ たいてい = usually / だいたい = roughly |
Rule: frequency is not the same as approximation. Original notes |
| B22 Verbs for wearing |
× 帽子をはく ○ 帽子をかぶる |
Rule: the item decides the verb. Original notes |
| B23 着る／切る |
× Both become きて ○ 着て／切って |
Rule: ichidan vs. godan verbs. Original notes |
| B24 Contracting てしまう |
× 読んちゃった ○ 読んじゃった |
Rule: でしまう -> じゃう. Original notes |
| B25 もう／まだ／また |
× “not yet” = また ○ “not yet” = まだ |
Rule: these are different time adverbs. Original notes |
| B26 何を／何か |
× Treating the two questions as synonyms ○ Specific content / whether anything exists |
Rule: they call for different kinds of answers. Original notes |
| B27 何で |
× 何で使いますか for every case ○ 何を使う／何に使う／どうやって使う |
Rule: first decide what role the question asks about. Original notes |
| B28 Asking for an item |
× このケーキでください ○ このケーキをください |
Rule: the item, as the object, takes を. Original notes |
| B29 これを／これで |
× Exactly the same meaning ○ Item / option or method |
Rule: を and で play different roles. Original notes |
| B30 Price sentences |
× ケーキを500円です ○ ケーキは500円です |
Rule: the sentence ends as an “A is B” statement. Original notes |
| B31 Quantity expressions |
Error pattern: を repeated after an object that is already marked, e.g. Tシャツを三枚を買う Corrected: Tシャツを三枚買う |
Scope revised in this edition: this targets a repeated particle within a full sentence; “三枚を買う” on its own is not automatically marked wrong. Original notes |
| B32 しか |
× 三時間しか寝ました ○ 三時間しか寝ませんでした |
Rule: しか is followed by a negative. Original notes |
| B33 いい |
× いくない ○ よくない |
Rule: irregular conjugation. Original notes |
| B34 きれい |
× きれくない／きれい部屋 ○ きれいではない／きれいな部屋 |
Rule: it is a na-adjective. Original notes |
| B35 ことにする |
× 行ったことにした (for a decision about the future) ○ 行くことにした |
Rule: keep the time of the content separate from the time of the decision. Original notes |
| B36 わけ |
× わけがない = “can’t, given my position” ○ “impossible” / わけにはいかない = “can’t, given my position” |
Rule: they work at different levels of meaning. Original notes |
| B37 てくる |
× Only ever translated as “come” ○ Space, time and the direction of an action |
Rule: look at the direction relative to the reference point. Original notes |
| B38 食べに／食べて |
× Both mean “go and eat” ○ Purpose / sequence of actions |
Rule: に = purpose; て = linking. Original notes |
| B39 予約 (reservation) |
× 予約を立てる ○ 予定を立てる／予約する |
Rule: fixed collocations. Original notes |
| B40 文化財 (cultural property) |
× 文物（ぶんかざい） ○ 文化財 |
Rule: match the kanji with its reading. Original notes |
| B41 上野 and かかる |
× 上野で電車に一時間をかかる ○ 上野まで電車で一時間かかる |
Rule: keep endpoint, means and duration apart. Original notes |
| B42 電話 (phone) |
× One particle for all of them ○ 電話で話す／電話をかける／電話に出る |
Rule: the case differs from predicate to predicate. Original notes |
| B43 だけ and しか |
× Both take a negative ○ だけ can be affirmative; しか must be negative |
Rule: neutral limitation vs. a sense of “not enough.” Original notes |
Source handbook pages: P77, P78, P79
42 | Connection table: だ／な／の／no だ
Before “plain form + X,” first check which form the non-past affirmative of nouns and na-adjectives takes.
Editor’s analysis
This table is the entry point for connections across the whole handbook. Read the pattern on the far right first, then the word class before it. 静かだと思う, 静かなので, 静かなとき, 静かでしょう do not contradict each other, because the structure on the right differs.
The table centers on the non-past affirmative. Do not carry “no だ” over to the past: 学生だったかもしれない still keeps its だった. The ため example of cause deliberately keeps the past-tense verb 遅れた, to show that a cause can also be something that has already happened.
The table merges connections that were scattered through the source. The noun connections for inference and appearance were also checked against the Tokyo University of Foreign Studies source W4, and から／ので against W1. Advanced patterns for which the source never set out a complete rule are not forced into a neat-looking formula.
| Connection type | Form on the right | Verb | い形 | な形 | Noun | Function |
|---|---|---|---|---|---|---|
| Plain form | から | 行くから | 寒いから | 静かだから | 休みだから | Cause; polite style also possible |
| な connection | ので | 行くので | 寒いので | 静かなので | 休みなので | Cause; polite style also possible |
| な connection | のに (concessive) | 行くのに | 寒いのに | 静かなのに | 休みなのに | Even though (against expectation) |
| な connection | んです | 行くんです | 寒いんです | 静かなんです | 休みなんです | Explaining the situation |
| な／の | とき | 行くとき | 寒いとき | 静かなとき | 休みのとき | Time setting |
| だ kept | と思う／と言う | 行くと思う | 寒いと思う | 静かだと思う | 休みだと思う | Content of a thought / statement |
| だ kept | そうだ (hearsay) | 行くそうだ | 寒いそうだ | 静かだそうだ | 休みだそうだ | I hear |
| だ dropped | かもしれない | 行くかもしれない | 寒いかもしれない | 静かかもしれない | 休みかもしれない | Possibility |
| だ dropped | でしょう | 行くでしょう | 寒いでしょう | 静かでしょう | 休みでしょう | Conjecture / confirmation |
| だ dropped | らしい (inference) | 行くらしい | 寒いらしい | 静からしい | 休みらしい | Indirect information / inference |
| な／の | はずだ | 行くはずだ | 寒いはずだ | 静かなはずだ | 休みのはずだ | Reasonable expectation |
| だ dropped | に違いない | 行くに違いない | 寒いに違いない | 静かに違いない | 休みに違いない | Strong conviction |
| な／の | ため (cause) | 遅れたため | 寒いため | 静かなため | 台風のため | Formal cause |
| Specified form | ために (purpose) | 勉強するために | 安くするために | 静かにするために | 健康のために | Purpose: volitional actions, etc. |
| Specified form | そうだ (appearance) | 降りそうだ | 寒そうだ | 元気そうだ | Does not attach directly to ordinary nouns | Masu stem / adjective stem |
| Plain form | し | 行くし | 寒いし | 静かだし | 休みだし | Listing; polite form also possible |
| Required verb form | Structure on the right | Example |
|---|---|---|
| Dictionary form | 前に／つもり／予定 | 寝る前に／行くつもり／帰国する予定 |
| ない形 | つもり／ほうがいい／ように言う | 行かないつもり／飲まないほうがいい／遅れないように言う |
| た形 | 後で／ことがある／ほうがいい | 食べた後で／行ったことがある／寝たほうがいい |
| て形 | いる／しまう／くる／いく／から | 読んでいる／読んでしまう／聞いてくる／帰ってから |
| ます語幹 | ながら／たい／方／に行く | 読みながら／読みたい／読み方／読みに行く |
Source handbook pages: P30, P80, P81, P87, P88, P89, P90, P91, P92, P94
43 | Tying the whole handbook together: four-layer check and review path
The final test is not whether you can recite the translations, but whether you can explain “why this form is here.”
Editor’s analysis
When reading, look first at the predicate and the roles; when doing exercises, check the connection on the right next. When building a sentence, write out the complete inner event first and add the tone last. Alternating between these two directions makes misplaced layers easier to spot than memorizing formulas alone.
What follows is not a new set of test questions or a new skill rating. It condenses the quick reference and ten-second check from the original P80–81 into a checking routine you can use again and again.
| Check layer | What to confirm | Contrast in the source |
|---|---|---|
| Event and roles | Who does it, to what, where, with what? | 電車に乗る／電車で行く |
| Inner/outer layers and time | Is it an action still to be done, a completed fact, something occasional or an experience? | 消すのを忘れた／消したのを忘れた |
| Connecting form | Does the right side need the dictionary form, the ta-form, the masu stem, or a special connection for the four word classes? | 静かだと思う／静かなんです |
| Intent and context | Is it stating a plan, a conjecture, a source, a request or something contrary to expectation? | 予定／つもり／でしょう／そうです |
The original ten-second check, restated to match this edition’s connection revisions
- What is the outermost predicate?
- Which predicate does each particle belong to?
- Is the noun the subject, the object, a place, a tool, a purpose or a standard of comparison?
- Which form does the pattern on the right require?
- Are the inner content and the result of the whole sentence mixed up?
- Does the から／ので cause clause use plain or polite style?
- Has a repeated particle been added by mistake near a quantity expression?
- Does the question ask for specific content, or whether there is anything at all?
- Are the time relations of もう／まだ／また correct?
- Is a word-for-word translation from your own language interfering with the Japanese case frame?
Reading paths
| Need | Reading order |
|---|---|
| Fix weak spots found in tests first | Error diagnosis → nominalization and 忘れる → giving and receiving → comparison / adverbs → the 43 common traps |
| Organize new handwritten pages | んです → cause / concession → advice → 予定／つもり → conjecture / そう → time limits → health collocations |
| Quick check before making sentences | Connection table → related examples → verb index |
| When sources contradict each other | Revision log → 95-page source map |
Source handbook pages: P2, P80, P81, P85
Revision log and items to confirm
“Original notes, rearranged” preserves the source’s teaching context; “Editor’s analysis” is the compiler’s analysis; only content marked as externally checked draws on the public materials listed below. The full text of the source handbook’s old edition and the images of its original pages are not public.
| Revision | Original problem | How this edition handles it | Source / topic |
|---|---|---|---|
| R01 Right/wrong mislabeling of 静かなんです |
An early chat marked the same string with both a cross and a check mark. | This edition keeps 静かなんです as the correct form; the incorrect example is now 静かだんです. |
Earlier reply, source P87 View topic |
| R02 Plain form ≠ dictionary form |
An early summary put “plain form / dictionary form” side by side, making them easy to mistake for synonyms. | The plain form covers four forms (affirmative or negative, non-past or past); patterns that specify the dictionary form are listed separately. |
P25、P30 View topic |
| R03 Polite-form connection with ので |
An early table listed only the plain form, which could easily turn into an exclusive rule. | Added that 行きますので／休みですので are also correct; polite requests can use ので as well. |
P87 + external check W1 View topic |
| R04 The “objective vs. subjective” mnemonic for から／ので |
Early versions used a brief “direct / objective” contrast. | Kept as a tendency in tone, not a hard classification into objective fact vs. subjective will. |
P42、P87＋W1 View topic |
| R05 Scope of dropping だ in the connection table |
Readers might apply “no だ after N／な形” to every tense. | Explicitly limited to the non-past affirmative; 学生だったかもしれません keeps だった. | P91＋W4 View topic |
| R06 Nにいい and について |
A note on what something is good for, at the bottom of an earlier page of handwritten notes, had been filed under a “について” topic. | Separated the two: Nにいい／Vるのにいい go back under use; について is kept as supplementary content from the previous edition. |
Handwritten notes, P89 View topic |
| R07 The とき table omitted the な form |
The condensed table on P94 did not fully separate N (nouns) from な形 (na-adjectives). | Restored 学生のとき／暇なとき from P40 and marked that they belong to different word classes. |
P40、P94 View topic |
| R08 予定／つもり are not about whether a ticket is booked |
“A decision in your head / an itinerary” is only a metaphor. | Compared by viewpoint (arrangement / intention / decision), without claiming that 予定 means a ticket is definitely booked or that つもり means nothing has actually been arranged yet. |
P68、P91＋W3 View topic |
| R09 楽しい／楽しみ ≠ present / future |
The previous edition split them into present enjoyment and future anticipation. | Now distinguished as evaluating a quality vs. anticipation or enjoyment; conjugation examples show that 楽しい can also describe the past and the future. |
P27, P94; examples in this edition View topic |
| R10 Not enough evidence to read it as 北海道 |
P95 had transcribed the faint characters as 北海道, already with a note of uncertainty. | Removed from the main vocabulary list. The handwritten notes may read 飛騨（ひだ）, but it stays listed as “to confirm”; one guess is not used to overwrite an older guess. |
Handwritten notes, P95 View topic |
| R11 三枚を買う should not be crossed out regardless of context |
B31 had compressed “を repeated after a quantity expression” into a short standalone phrase. | Restored the full example Tシャツを三枚を買う; the target is the repeated case marker, not a ban on every quantity + particle combination. | P17、P79 View topic |
| R12 どちら is not a polite substitute for every どれ |
The generalization on P94 could conflict with the two-vs-many contrast on P57. | Restored the contexts of direction, people and choice; the handbook’s basic pattern is どちら for choosing between two and どれ for choosing one of many. |
P9–10、P57、P94 View topic |
| R13 ようになる is not necessarily gradual |
The previous edition explained it as “gradually becomes.” | The core is now a change of state, habit or ability between before and after; whether it is gradual is decided separately by context. |
P90; this edition’s note on the scope of meaning View topic |
| R14 Quantified probabilities and inferences about ability |
The original notes had “higher likelihood” labels and past test scores. | Grammar is not turned into fixed probabilities, and old test scores are not treated as current ability or a JLPT level. |
P3、P91 View topic |
| R15 Content boundaries for advanced patterns and faint text |
にもかかわらず, によって and others have only fragments or a few examples; the bottom of the handwritten notes is cut off. | Does not claim to be a complete dictionary or a complete advanced grammar course; keeps to what the source supports, and faint or cut-off text is still marked unconfirmed. |
P88, P94, handwritten notes View topic |
| R16 Overly sharp split between もみじ and 紅葉 |
The handwritten notes distinguish them as the tree vs. the color of the leaves; the earlier HTML did not fully include this. | Added the original learning contrast, without limiting もみじ to a single tree species or 紅葉 to a single reading. |
Handwritten notes; added in this edition View topic |
| R17 The example 高くて便利です |
The i-adjective te-form example “高くて便利です” is unnatural in meaning: it is hard to tell whether it means “tall and convenient” or “expensive and convenient.” | Changed to 山が高くて、きれいです。 This shows the te-form joining parallel descriptions. |
Checked on this site 2026-10-12 View topic |
95-page source map
Every one of the source handbook’s 95 pages has a new location. P1–P95 here are page markers from the original merged file, not page numbers on this site; the text and images of the original pages are not public.
Expand the map of the 95 pages and their topics
Sources for external checks
The public materials below were used only to check the connections and tone flagged in this edition; they were not used to replace the original materials as a whole. They were consulted for the original on 2026-10-10, and the links were checked again when the notes were rewritten for this site (2026-10-12).
- W1 Tokyo University of Foreign Studies | 理由 (reasons) Both plain and polite forms can take から and ので; tone, and limits with requests and commands.
- W2 Tokyo University of Foreign Studies | 接続助詞 (conjunctive particles) Listing with たり／し; し can be seen attaching to polite forms.
- W3 The Japan Foundation | 文法を楽しく：つもり（1） The viewpoints of つもり, 予定 and ことにする; the scope of on-the-spot decisions and volitional uses.
- W4 Tokyo University of Foreign Studies | かもしれません・にちがいありません Connections for inference, はず and そう／らしい; the appearance そう does not attach directly to nouns.
- W5 Tokyo University of Foreign Studies | でしょう Pragmatic functions of でしょう such as conjecture and confirmation.
How this site’s edition was prepared, and its limits
- Personal test scores and answer statistics from the source handbook are not published; section 02 keeps only the types of errors and their root causes.
- The 7 photos of handwritten notes, the images of 85 original pages and the 95-page full text of the old edition are not published. Their content has been merged into the 43 topics, and the source page numbers are kept in the map above.
- The original version’s read markers, font-size controls, Chinese-hiding toggle and settings export all relied on the browser’s local storage; this site uses no storage at all, so they were not carried over. To test yourself, cover the meaning column first and then try to recall.
- Japanese example sentences stay in the original in all three editions (Traditional Chinese, English and Japanese). The explanations in the English and Japanese editions were translated by this site, and the Japanese edition omits Chinese glosses that would only repeat the examples. The translations have not been reviewed item by item by a Japanese teacher.
- The 43 topics are split into 7 parts and linked into a series following the original grouping; section numbers and anchors are carried over from the original.
- Some Japanese fields in the source handbook mixed in Chinese labels or meanings, such as a Chinese gloss after a reading; this edition moves the Chinese outside the Japanese so all three editions can translate it. In note 6, 上半身衣物を着る mixed in a Chinese word and now reads 上半身の服を着る.