失敗 (Shippai) vs. 間違い (Machigai): Failure in Results vs. Mistakes in Judgment

Introduction

Japanese learners often confuse 失敗 (shippai / failure) and 間違い (machigai / mistake).

That is understandable. Both words describe a situation in which something did not go as it should. Depending on the context, both may also be translated into English using words such as “mistake,” “failure,” “error,” or “wrong.”

However, they do not focus on the same part of the situation.

失敗 (shippai / failure) usually focuses on an action, attempt, or project that did not produce the desired result.

間違い (machigai / mistake) usually focuses on something that was not correct, such as an answer, decision, choice, method, or piece of information.

Because their meanings overlap, using the wrong word will not always make your sentence impossible to understand. Even so, it can make otherwise correct Japanese sound slightly unnatural.

Let us begin with some common mistakes and see how native speakers distinguish these two words.

A Common Learner Mistake

Consider the following sentence:

昨日のテストで失敗を三つしました。
I made three failures on yesterday’s test.

The intended meaning is probably clear. The speaker wants to say that three answers on the test were incorrect.

However, 失敗 is not the natural choice when counting individual incorrect answers.

A more natural sentence is:

昨日のテストで間違いを三つしました。
I made three mistakes on yesterday’s test.

An even more natural way to say it is:

昨日のテストで三問間違えました。
I got three questions wrong on yesterday’s test.

Now consider another example:

新しい事業は大きな間違いに終わった。
The new business ended in a major mistake.

The meaning can still be understood, but if the speaker wants to say that the business did not succeed, 失敗 is more natural.

新しい事業は大きな失敗に終わった。
The new business ended in a major failure.

間違い focuses on whether a judgment or choice was correct. 失敗 focuses on whether an attempt or project succeeded.

Why Does the Wrong Word Sound Unnatural?

The confusion occurs because both words contain the idea that something went wrong.

The important question is:

What exactly went wrong?

間違い (machigai / mistake) is commonly used when something is incorrect.

For example:

• An answer is incorrect.
• A calculation is incorrect.
• Information is incorrect.
• A decision is wrong.
• The wrong option was selected.
• A method or procedure is incorrect.

失敗 (shippai / failure) is commonly used when an attempt does not achieve its intended result.

For example:

• A plan does not work.
• A goal is not achieved.
• An experiment does not produce the expected result.
• A negotiation is unsuccessful.
• A challenge ends without success.

In simple terms, 間違い often focuses on correctness, while 失敗 focuses on success or results.

Compare these two sentences:

店の選び方を間違えた。
I chose the restaurant in the wrong way. / I made the wrong choice of restaurant.

This sentence focuses on an incorrect choice or judgment.

レストランの予約に失敗した。
I failed to make a restaurant reservation.

This sentence focuses on an unsuccessful result. The speaker tried to reserve a table but was unable to do so.

Natural Corrections

Incorrect Example 1

昨日のテストで失敗を三つしました。
I made three failures on yesterday’s test.

Natural Japanese

昨日のテストで間違いを三つしました。
I made three mistakes on yesterday’s test.

昨日のテストで三問間違えました。
I got three questions wrong on yesterday’s test.

Here, individual answers were incorrect, so 間違い or the verb 間違える (machigaeru / to get something wrong) is appropriate.

However, if you are evaluating your overall performance on the test, 失敗 can be used.

昨日のテストは失敗だった。
Yesterday’s test was a failure for me.

This sentence does not refer to a specific answer. It evaluates the entire test result.

Incorrect Example 2

新しい事業は大きな間違いに終わった。
The new business ended in a major mistake.

Natural Japanese

新しい事業は大きな失敗に終わった。
The new business ended in a major failure.

The project did not achieve its goals, so the sentence focuses on the final result.

However, 間違い is possible when the speaker is criticizing the decision to begin the business.

十分な調査をせずに事業を始めたのは、経営上の大きな間違いだった。
Starting the business without conducting sufficient research was a major management mistake.

Here, the focus is not simply on the business result. The speaker believes that the decision itself was wrong.

The Basic Difference Between 失敗 and 間違い

失敗 (shippai / failure) means that someone tried to do something but did not achieve the intended or expected result.

It is commonly used for attempts, projects, experiments, exams, negotiations, operations, plans, and challenges.

間違い (machigai / mistake) means that an answer, idea, judgment, selection, piece of information, method, or action was not correct.

A useful way to remember the difference is:

• 失敗: Something did not succeed.
• 間違い: Something was not correct.

A 間違い can also become the cause of a 失敗.

判断を間違えたため、プロジェクトに失敗した。
Because we made the wrong judgment, the project failed.

In this sentence, the incorrect judgment is the 間違い, and the unsuccessful project result is the 失敗.

Learn the Difference Through Examples

Example 1

電話番号を間違えて、知らない人に電話してしまった。
I entered the wrong phone number and accidentally called someone I did not know.

The phone number was incorrect, so 間違える is natural.

Japanese speakers would not normally say 電話番号を失敗する.

Example 2

初めてケーキを作ったが、焼きすぎて失敗した。
I made a cake for the first time, but I overbaked it and it did not turn out well.

The attempt to make the cake did not produce the desired result, so 失敗した is appropriate.

Example 3

この計算には間違いがあります。
There is an error in this calculation.

The calculation or its answer is incorrect, so 間違い is used.

この計算には失敗があります。
There is a failure in this calculation.

This sounds unnatural because a calculation contains an error, not an unsuccessful attempt.

Example 4

会社は海外進出に失敗し、大きな損失を出した。
The company failed in its overseas expansion and suffered a major loss.

The overseas expansion did not succeed, so 失敗 is natural.

Example 5

私は電車を間違えて、反対方向へ行ってしまった。
I took the wrong train and went in the opposite direction.

The speaker selected the wrong train, so 間違える is used.

電車に失敗した。
I failed at the train.

This is not natural Japanese.

Example 6

面接では緊張しすぎて、うまく話せなかった。完全な失敗だった。
I was too nervous during the interview and could not speak well. It was a complete failure.

The speaker is evaluating the overall result of the interview, so 失敗 is appropriate.

Example 7

彼を責任者に選んだのは間違いだったかもしれない。
Choosing him as the person in charge may have been a mistake.

The focus is on whether the decision was correct, so 間違い is natural.

Example 8

実験は失敗したが、その原因を調べることで新しい発見があった。
The experiment failed, but investigating the cause led to a new discovery.

The expected experimental result was not obtained, so 失敗した is used.

If the problem was an incorrect procedure, the sentence would be different:

実験の手順に間違いがあった。
There was a mistake in the experimental procedure.

Example 9

入力するパスワードを間違えた。
I entered the wrong password.

The password entered was incorrect, so 間違えた is natural.

If the speaker could not access the system, Japanese focuses on the unsuccessful result:

システムへのログインに失敗した。
I failed to log in to the system.

The two sentences can describe the same event from different perspectives.

The first focuses on the incorrect password. The second focuses on the failed login.

Example 10

道を間違えたため、約束の時間に間に合わなかった。
Because I took the wrong route, I did not arrive in time for the appointment.

The chosen route was incorrect, so 道を間違えた is natural.

時間の計算を誤り、旅行の計画は失敗に終わった。
We miscalculated the time, and the travel plan ended in failure.

The miscalculation was the mistake, and the unsuccessful travel plan was the result.

When Both Words Are Possible

Sometimes both 失敗 and 間違い can be used, but the meaning changes.

Compare the following sentences:

結婚は失敗だった。
The marriage was a failure.

This means that the marriage or married life did not work out well. The speaker is evaluating the result.

結婚は間違いだった。
The marriage was a mistake.

This means that getting married, or choosing that person as a spouse, was the wrong decision.

The same difference appears here:

転職は失敗だった。
Changing jobs was a failure.

The new job or the result of changing jobs did not meet expectations.

転職したのは間違いだった。
Changing jobs was a mistake.

The speaker believes the decision to change jobs was wrong.

When both words seem possible, ask yourself whether the sentence is evaluating the result or the decision.

• Result: 失敗
• Decision or correctness: 間違い

Common Word Combinations

失敗 is often used with activities and attempts:

• 実験に失敗する
  to fail in an experiment
• 手術に失敗する
  to fail in an operation
• 受験に失敗する
  to fail an entrance examination
• 交渉に失敗する
  to fail in negotiations
• ダイエットに失敗する
  to fail at dieting
• ログインに失敗する
  to fail to log in
• 事業に失敗する
  to fail in business
• 計画が失敗に終わる
  for a plan to end in failure

間違い is often used with things that can be correct or incorrect:

• 答えを間違える
  to get an answer wrong
• 計算を間違える
  to make a calculation error
• 名前を間違える
  to get someone’s name wrong
• 道を間違える
  to take the wrong route
• 電車を間違える
  to take the wrong train
• 判断を間違える
  to make the wrong judgment
• 選択を間違える
  to make the wrong choice
• 方法が間違っている
  for a method to be incorrect
• 情報に間違いがある
  for information to contain an error

Pay attention to the particles as well.

間違える commonly takes a direct object marked by を.

答えを間違える。
To get an answer wrong.

道を間違える。
To take the wrong route.

失敗する is commonly used with に when describing an unsuccessful attempt.

実験に失敗する。
To fail in an experiment.

交渉に失敗する。
To fail in negotiations.

This particle difference may also appear in JLPT questions.

How JLPT Questions Try to Confuse You

In JLPT vocabulary questions, 失敗 and 間違い may appear together as possible answers because their meanings are close.

The key is to identify whether the sentence is describing something incorrect or an unsuccessful result.

Consider this question:

書類に名前を書く場所を（　　　）しまった。
I accidentally got the place where I should write my name on the document wrong.

If the choices include 失敗して and 間違えて, the natural answer is 間違えて.

書類に名前を書く場所を間違えてしまった。
I accidentally wrote my name in the wrong place on the document.

The location selected was incorrect.

Now consider this sentence:

何度も練習したが、本番の演奏に（　　　）しまった。
I practiced many times, but I failed during the actual performance.

Here, 失敗して is natural.

何度も練習したが、本番の演奏に失敗してしまった。
I practiced many times, but I failed during the actual performance.

The performance did not achieve the expected result.

In reading questions, you may also need to distinguish between the cause and the result.

情報が間違っていたため、計画は失敗した。
Because the information was incorrect, the plan failed.

The information was wrong, so it is described with 間違い. The plan was unsuccessful, so it is described with 失敗.

When choosing an answer, ask:

• Is an answer or piece of information incorrect?
• Was a choice or judgment wrong?
• Did an attempt or project fail to achieve its goal?
• Is the sentence describing the cause or the final result?

If the issue is “correct or incorrect,” choose 間違い.

If the issue is “successful or unsuccessful,” choose 失敗.

Summary

失敗 and 間違い both describe situations in which something went wrong, but they focus on different things.

• 失敗: An attempt, action, or project did not produce the intended result.
• 間違い: An answer, judgment, choice, method, or piece of information was incorrect.

A mistake can also cause a failure:

選択を間違えた結果、計画に失敗した。
As a result of making the wrong choice, the plan failed.

For the JLPT, knowing a dictionary definition is not always enough. You need to decide whether the context is about correctness, judgment, or the final result.

RJT (Rapid Japanese Training) helps you develop this skill through short practice sessions based on realistic Japanese questions. By repeatedly comparing the correct answer with similar but incorrect choices, you can learn to recognize the expressions that sound natural in context.

Build the ability to choose the right word, even when several options look almost correct:

https://rapid-jt.com/