What is the difference between 「のみならず」 and 「ばかりか」? How to express expansion in formal Japanese writing

When reading Japanese essays, news articles, explanations, or JLPT N2 reading passages, you often see formal expressions that add another idea to the sentence.

For example:

「この制度は学生のみならず、社会人にも役立つ。」
This system is useful not only for students, but also for working adults.

「この制度は学生ばかりか、社会人にも役立つ。」
This system is useful not only for students, but even for working adults.

Both sentences seem to mean “not only A, but also B.”

So, are 「のみならず」 and 「ばかりか」 the same?

They are close, but not identical.

「のみならず」 mainly expands the range of the topic. It means that something is not limited to A, but also applies to B.

「ばかりか」 also means “not only,” but it often adds a stronger, more surprising, or more emphatic idea after it.

In simple terms:

「のみならず」 = expansion of range
「ばかりか」 = expansion plus emphasis or surprise

Understanding this difference helps you read formal Japanese more accurately.

The basic idea

「のみならず」 is a formal expression meaning “not only.”

The pattern is:

AのみならずBも

It means:

not only A, but also B

The focus is on expanding the range from A to B.

For example:

「この問題は日本のみならず、世界各国で議論されている。」
This issue is being discussed not only in Japan, but also in countries around the world.

Here, the topic expands from Japan to the world. The sentence sounds calm and objective.

On the other hand, 「ばかりか」 also means “not only,” but it often suggests:

A is already significant, but B is also true.

For example:

「彼は遅刻したばかりか、謝りもしなかった。」
He was late, and not only that, he did not even apologize.

Here, the sentence does not simply list two facts. It shows that being late was already bad, and not apologizing made it even worse.

That is the key difference.

「のみならず」 expands.
「ばかりか」 intensifies.

「のみならず」 expands the range

「のみならず」 is often used in formal writing, academic texts, business documents, speeches, and news-style Japanese.

It is less common in casual conversation.

Look at this sentence:

「この教材は文法学習のみならず、読解力の向上にも役立つ。」
This learning material is useful not only for grammar study, but also for improving reading ability.

Here, the writer is calmly adding another area where the material is useful.

The focus is not surprise. The focus is range.

The material helps with grammar.
It also helps with reading.

So 「のみならず」 is a good choice.

Another example:

「少子高齢化は地方のみならず、大都市にも影響を与えている。」
The aging population and declining birthrate affect not only rural areas, but also large cities.

Again, the sentence expands the range from rural areas to large cities.

This is typical of 「のみならず」.

「ばかりか」 adds stronger emphasis

「ばかりか」 also adds B after A, but the second part often feels stronger, more surprising, more serious, or more impressive.

For example:

「この薬は効果がないばかりか、副作用まで出た。」
This medicine not only had no effect, but also caused side effects.

The first part, 「効果がない」, is already negative.

The second part, 「副作用まで出た」, makes the situation even worse.

This is why 「ばかりか」 often feels close to “what is more” or “on top of that.”

Another example:

「彼女は日本語が話せるばかりか、専門的な通訳もできる。」
She can not only speak Japanese, but also do professional interpreting.

Here, 「日本語が話せる」 is already a good ability.

But 「専門的な通訳もできる」 is even more impressive.

So 「ばかりか」 emphasizes the high level of her ability.

Neutral expansion vs. emphatic addition

One useful way to remember the difference is this:

「のみならず」 is relatively neutral.
「ばかりか」 is more emphatic.

For example:

「この活動は子どもの成長のみならず、地域交流にも役立っている。」
This activity is useful not only for children’s growth, but also for community interaction.

This is calm and objective.

Now compare:

「この活動は子どもの成長に役立つばかりか、地域全体のつながりも強めている。」
This activity not only helps children grow, but also strengthens the connections of the whole community.

This sounds stronger. The second part feels like a bigger additional benefit.

That is why 「ばかりか」 often makes the sentence more dramatic.

When they can be replaced

Sometimes, both expressions can be used.

「この映画は若者のみならず、高齢者にも人気がある。」
This movie is popular not only among young people, but also among older people.

「この映画は若者ばかりか、高齢者にも人気がある。」
This movie is popular not only among young people, but even among older people.

The basic meaning is similar.

However, the nuance is different.

With 「のみならず」, the sentence calmly says that the movie is popular across a wide range of people.

With 「ばかりか」, the sentence suggests that its popularity is broader than expected.

So even when both are possible, 「ばかりか」 often adds a stronger feeling.

When 「ばかりか」 is more natural

Look at this sentence:

「彼は反省しないばかりか、同じ失敗を繰り返した。」
He not only failed to reflect on his mistake, but repeated the same mistake.

Here, 「反省しない」 is already a problem.

But 「同じ失敗を繰り返した」 makes the situation worse.

This sentence has a clear “not only that, but even worse” feeling.

So 「ばかりか」 is very natural.

You could say:

「彼は反省しないのみならず、同じ失敗を繰り返した。」

This is grammatically possible, but it sounds more formal and less natural in this context.

Because the sentence expresses criticism and escalation, 「ばかりか」 fits better.

When 「のみならず」 is more natural

Now look at this sentence:

「この研究は医学のみならず、教育学の分野にも応用できる。」
This research can be applied not only to medicine, but also to the field of education.

Here, the writer is calmly expanding the range of application.

There is no strong surprise, criticism, or emotional emphasis.

So 「のみならず」 is natural.

You could use 「ばかりか」 in some contexts, but it would add a stronger feeling than necessary.

For clear formal writing, 「のみならず」 is often the safer choice when you simply want to expand the range.

How to read them in JLPT reading passages

In JLPT reading, when you see 「のみならず」, ask:

What range is being expanded?

For example:

「日本のみならず、世界各国で」
not only Japan, but countries around the world

「学生のみならず、社会人にも」
not only students, but also working adults

「文法のみならず、読解にも」
not only grammar, but also reading

In these cases, the writer is expanding the target or scope.

When you see 「ばかりか」, ask:

Is the second part stronger, more surprising, worse, or more impressive?

For example:

「効果がないばかりか、副作用まで出た」
not only had no effect, but even caused side effects

「遅刻したばかりか、謝りもしなかった」
not only was late, but did not even apologize

「話せるばかりか、通訳もできる」
not only can speak, but can even interpret

In these cases, the second part carries stronger emphasis.

Example comparison

「このサービスは日本のみならず、海外でも利用されている。」
This service is used not only in Japan, but also overseas.

This sentence focuses on range.

Now compare:

「このサービスは日本で人気があるばかりか、海外でも高く評価されている。」
This service is not only popular in Japan, but also highly evaluated overseas.

This sentence emphasizes the strength of the evaluation.

Another pair:

「彼は漢字のみならず、敬語の使い方にも詳しい。」
He is knowledgeable not only about kanji, but also about how to use honorific language.

This expands the area of knowledge.

「彼は漢字に詳しいばかりか、古典文法まで説明できる。」
He is not only knowledgeable about kanji, but can even explain classical grammar.

This emphasizes that his ability is greater than expected.

A common mistake

Many learners memorize both 「のみならず」 and 「ばかりか」 simply as “not only.”

That is not wrong as a basic translation.

But in real Japanese, the nuance matters.

「のみならず」 tells you that the range is expanding.

「ばかりか」 tells you that the second part is especially important, surprising, strong, or serious.

In reading passages, the part after 「ばかりか」 may contain the writer’s stronger point.

So when you see 「ばかりか」, pay close attention to what comes after it.

Summary

「のみならず」 and 「ばかりか」 are both formal expressions that mean “not only.”

However, they are not exactly the same.

「のみならず」 is used when the writer wants to expand the range of a topic.

AのみならずBも
not only A, but also B

「ばかりか」 is used when the writer wants to add something stronger, more surprising, more serious, or more impressive.

AばかりかBも
not only A, but even B

To put it simply:

「のみならず」 = range expands
「ばかりか」 = meaning becomes stronger

Once you understand this difference, formal Japanese passages become easier to follow. You can see whether the writer is simply adding information or emphasizing a stronger point.

At RJT, you can learn similar Japanese grammar patterns through examples, explanations, audio, and a pop-up dictionary. If you want to improve not only grammar knowledge but also reading judgment, start learning from the page below.

https://rapid-jt.com/