The Most Common English Grammar Mistakes Japanese Writers Make (and How to Fix Them)

Japanese is one of the most structurally different languages from English in the world. The grammar works in almost the opposite direction. The vocabulary encodes meaning that English handles through entirely different mechanisms. And the rhetorical conventions of Japanese academic and professional writing pull in directions that English-language readers find confusing or indirect.

The result is a specific, predictable set of English grammar mistakes Japanese writers make. Not because of insufficient effort or limited proficiency, but because of the deep structural logic of Japanese itself. Understanding where these mistakes come from is the fastest way to stop making them.

This guide covers the twelve most common errors, explains the Japanese grammatical source of each one, and shows exactly how to fix it.

1. Missing or Wrong Articles: "A," "An," and "The"

This is the single most pervasive and persistent error in Japanese-authored English. Japanese has no articles. There is no grammatical equivalent of "a," "an," or "the" in Japanese. Context and shared understanding carry the distinctions that articles encode in English. For Japanese writers, every article decision requires conscious thought that native English speakers make automatically.

A short paragraph written by a Japanese professional may contain five or six article errors. Each one is immediately visible to any native English reader and creates a cumulative impression of non-native writing that distracts from the content.

The Fix

• Use "a" or "an" when introducing something for the first time, or when referring to one of a general category: "We conducted a survey." "She submitted an application."
• Use "the" when both writer and reader know which specific thing is being referred to: "The survey revealed three key findings." "Please review the attached report."
• Use no article with uncountable nouns in a general sense: "Research shows that..." "Information is available on request."

A practical check: every time you write a singular countable noun such as "report," "meeting," "proposal," or "study," ask whether it needs an article. The answer is almost always yes.

2. Omitting the Subject of a Sentence

Japanese allows, and often prefers, dropping the subject when it can be inferred from context. This is grammatically correct and stylistically natural in Japanese. In English, omitting the subject produces a grammatical error or an ambiguous sentence.

This error is particularly serious in academic and business writing, where it produces dangling modifiers: introductory phrases that appear to modify the wrong word because the expected subject has been left out.

Common errors

• Incorrect: "After reviewing the data, significant differences were found."
• Correct: "After reviewing the data, the researchers found significant differences."

• Incorrect: "In this study, examined the relationship between income and behavior."
• Correct: "In this study, we examined the relationship between income and behavior."

The Fix

Every English sentence needs an explicit grammatical subject. Before submitting any document, scan each sentence and confirm that the subject is stated, not implied. Pay particular attention to sentences that begin with an introductory phrase. The subject of that phrase must match the subject of the main clause.

3. Verb at the End of the Sentence

Japanese is a Subject-Object-Verb (SOV) language. The verb comes at the end of the sentence, after the object and all modifying elements. English is Subject-Verb-Object (SVO). The verb follows the subject directly. Japanese writers who are still internalizing English word order sometimes produce sentences where the verb appears too late, or where embedded clauses are stacked before the main verb in ways that feel natural in Japanese but are difficult to parse in English.

Common error

• Incorrect: "The hypothesis that the research team after reviewing all available literature proposed was not supported."
• Correct: "The hypothesis proposed by the research team, after their review of the available literature, was not supported."

The Fix

Keep the subject and verb close together in English sentences. If you find yourself writing a long string of modifying clauses before reaching the verb, restructure the sentence to bring the verb forward. Place modifying phrases after the core subject-verb-object structure wherever possible.

4. Relative Clauses in the Wrong Position

In Japanese, relative clauses come before the noun they modify. In English, they come after. This produces a characteristic structural error in Japanese-influenced English where modifying information appears before the noun rather than after it.

Common error

• Incorrect: "The [who submitted the report last week] researcher received positive feedback." (Japanese logic translated literally)
• Correct: "The researcher who submitted the report last week received positive feedback."

The Fix

In English, the relative clause (beginning with "who," "which," "that," "where," or "when") follows immediately after the noun it describes. If you notice a modifier appearing before a noun rather than after it, move it to the correct position.

5. Passive Voice Overuse

Japanese academic and business writing strongly favors passive constructions. Passive voice is considered more formal, more objective, and more appropriate for scholarly and professional contexts in Japanese. Japanese writers carry this preference directly into English, producing documents that use passive voice almost exclusively, including sections where international readers and journal editors expect active voice.

This is one of the most commented-on features of Japanese-authored English manuscripts in peer review. Reviewers consistently describe passive-heavy writing as indirect, unclear, and difficult to follow.

Common errors

• Passive: "It was decided by the committee that the deadline would be extended."
• Active: "The committee decided to extend the deadline."

• Passive: "The samples were collected and analyzed by the research team."
• Active: "The research team collected and analyzed the samples."

The Fix

Check every sentence for passive voice. In most cases, converting to active voice makes the sentence shorter, clearer, and easier to follow. Passive voice is appropriate when the actor is unknown, genuinely unimportant, or when you are deliberately avoiding assigning responsibility. In all other cases, prefer active voice, particularly in methods sections, business proposals, and executive communications.

6. Countable and Uncountable Noun Errors

Japanese does not have a grammatical distinction between countable and uncountable nouns equivalent to English. This produces a consistent and highly visible set of errors in Japanese-authored English documents, where words that are uncountable in English are pluralized or preceded by "a."

Common errors

• "informations" — information is uncountable. Say "information" or "pieces of information."
• "researches" — as a noun, research is uncountable. Say "research" or "studies."
• "evidences" — evidence is uncountable. Say "evidence."
• "advices" — advice is uncountable. Say "advice" or "pieces of advice."
• "feedbacks" — feedback is uncountable. Say "feedback."
• "knowledges" — knowledge is uncountable. Say "knowledge."
• "a homework" — homework is uncountable. Say "homework" or "an assignment."

The Fix

Memorize the most common uncountable nouns used in your field. Before submitting any document, search for these words specifically and check whether you have incorrectly pluralized them or preceded them with "a" or "an."

7. Preposition Errors

Japanese uses postpositions (particles that follow nouns) to indicate grammatical relationships such as location, direction, purpose, and time. English uses prepositions that precede nouns, and the mapping between Japanese particles and English prepositions is not one-to-one. Many English prepositions must be learned as collocations: fixed pairings with specific verbs, nouns, or adjectives that cannot be predicted by logic alone.

Common errors

• "interested on" — say "interested in"
• "depend to" — say "depend on"
• "different with" — say "different from"
• "participate to" — say "participate in"
• "based in the data" — say "based on the data"
• "associated to" — say "associated with"
• "consist with" — say "consist of"
• "discuss about" — say "discuss" (no preposition needed)

The Fix

Preposition collocations cannot be fully learned through rules. They require exposure and practice. Keep a personal reference list of preposition collocations that appear frequently in your field. When in doubt, search for the phrase in a corpus of published writing in your discipline to check which preposition is standard.

8. Topic-Comment Structure Instead of Subject-Predicate

Japanese is a topic-prominent language. Sentences typically begin with a topic, marked by the particle は (wa), followed by a comment about that topic. The topic does not have to be the grammatical subject of the sentence. This produces a characteristic pattern in Japanese-influenced English: sentences that begin with a topic phrase that does not correspond to a clear grammatical role, often introduced by "As for..." or "Regarding..."

Common errors

• Incorrect: "As for the methodology, three steps were followed by the researchers."
• Better: "The researchers followed three methodological steps."

• Incorrect: "Regarding the results, significant differences were observed."
• Better: "The analysis revealed significant differences."

The Fix

The "As for..." and "Regarding..." constructions are not grammatically incorrect in English, but they are overused in Japanese-influenced writing because they reflect the topic-comment habit. They also tend to generate unnecessary passive constructions. In most cases, restructure the sentence to lead with a clear grammatical subject performing a clear action.

9. Tense Inconsistency

Japanese expresses tense through verb endings that function differently from English tense, and the relationship between Japanese tense markers and English tense conventions is not direct. Japanese writers frequently shift tenses within a passage in ways that feel consistent in Japanese but create errors in English.

In academic writing, tense conventions are specific by section:

• Methods section: past tense throughout. "Data were collected from 450 participants."
• Results section: past tense throughout. "The analysis revealed three significant factors."
• Introduction, established facts: present tense. "Risk tolerance influences investment behavior."
• Discussion, general claims: present tense. "These findings suggest that advisors should consider..."

The Fix

The most common error is using present tense throughout, including for completed research procedures. Check every verb in your Methods and Results sections and confirm they are in past tense. This is one of the first things journal editors notice when assessing whether a manuscript has been reviewed by a native English speaker.

10. Long, Stacked Modifier Chains

Japanese allows and stylistically prefers long chains of modifying elements stacked before the main noun or verb. Translated into English, this produces sentences where the reader must wade through lengthy embedded material before reaching the point. English business and academic writing values directness. The point should come early. Supporting detail follows.

Common error

• Problematic: "The methodology the research team developed after reviewing the existing literature on this topic was applied to the dataset."
• Clearer: "The research team applied a methodology developed from their literature review."

The Fix

If a sentence has more than two modifying elements before its main subject or verb, restructure it. State the main subject and verb first. Then add supporting detail in phrases that follow, using relative clauses, prepositional phrases, or separate sentences.

11. Honorific Formality Translated as Verbose English

Japanese has a highly developed system of speech levels and honorifics that signal social relationships. There is no equivalent system in English. Japanese writers attempting to signal appropriate formality in English sometimes produce writing that is elaborate, roundabout, and verbose. This is because they're signaling respect through linguistic complexity, a strategy that works in Japanese honorific speech but reads as unclear and inefficient in English.

Common error

• Overly elaborate: "We would be most humbly grateful if you would be so kind as to give your most gracious consideration to the attached proposal at your earliest possible convenience."
• Appropriately formal: "We would appreciate your review of the attached proposal at your convenience."

The Fix

English business formality is expressed through professional vocabulary and appropriate structure, not through elaborate phrasing. Directness is not rudeness in English business culture. State your request clearly and professionally. Cut any phrase that exists only to signal deference rather than to communicate information.

12. Weak or Missing Gap Statements in Academic Writing

Japanese academic rhetoric builds extensive background context before arriving at the research question. This reflects a rhetorical convention that values thorough orientation before the main point. International English-language journals follow the opposite convention: the research gap and research purpose must appear early and explicitly in the introduction.

When Japanese researchers write introductions that build context extensively without an explicit gap statement, international peer reviewers conclude that the justification for the study is weak, even when the research itself is rigorous.

The Fix

State the research gap explicitly and early: "However, no previous study has examined..." or "A gap remains in our understanding of..." This sentence is what justifies the existence of your paper. Do not expect the reader to infer the gap from your literature review. State it directly.

Why These Errors Are So Hard to Self-Correct

Every error in this list has the same underlying reason: it feels correct to the writer. Article errors feel correct because Japanese has no articles. Passive voice feels correct because it is preferred in Japanese professional writing. Subject omission feels correct because it is grammatically valid in Japanese. The stacked modifier structure feels correct because it is natural in Japanese sentence construction.

Self-editing cannot fully solve this problem. You read what you intended to write rather than what is on the page. The errors that are most invisible to you are precisely the ones that reflect the deepest structural habits of your first language. A native English editor sees them immediately because they violate the editor's own grammatical intuitions — and that intuition is what self-correction cannot replicate.

For a deeper look at how these patterns affect research paper submission and how professional editing addresses them before manuscripts reach peer review, read our article on why Japanese research papers get rejected and how native English editing fixes it.

Professional English Editing for Japanese Writers

Editor World's English editing services for non-native speakers connect Japanese writers with native English editors from the United States, United Kingdom, and Canada who have extensive experience working with Japanese-authored documents across academic, business, and professional contexts. You choose your own editor from verified profiles by subject expertise, credentials, and client ratings. Every editor has passed a rigorous credentials review. No AI tools are used at any stage.

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