JapaneseJLPT
JLPT N3 grammar · Chapter 23

～一方だ

A change keeps progressing more and more

You’ll be able to describe a trend that continues in a single direction without signs of reversing.

Illustration of the scene described by As the sun sets, it only keeps getting darker and darker inside the mountains.
Read it first

日ひが沈しずむにつれて、山やまの中なかは暗くらくなる一方いっぽうです。

hi ga shizumu ni tsurete, yama no naka wa kuraku naru ippou desu.

What do you think this sentence means?

As the sun sets, it only keeps getting darker and darker inside the mountains.

Why it means that

Describe an accelerating trend in one direction

Attach 一方いっぽうだ to a verb of change to emphasize that a condition or trend is progressing continuously in one single direction ("continues to... more and more").

Examples

この町まちに来くる人ひとは増ふえる一方いっぽうだ。

kono machi ni kuru hito wa fueru ippou da.

The number of people coming to this town just keeps increasing.

冬ふゆが近ちかづいて、朝あさは寒さむくなる一方いっぽうだ。

fuyu ga chikazuite, asa wa samuku naru ippou da.

With winter coming, the mornings just keep getting colder.

How it is built

Attach 一方だ to a verb of change

Attach 一方いっぽうだ directly to the dictionary form of a verb indicating progressive change.

verb (dictionary form of change)+一方だ
Example

地球ちきゅう温暖化おんだんかの影響えいきょうで、各地かくちの気温きおんは上昇じょうしょうする一方いっぽうだ。

chikyuu ondanka no eikyou de, kakuchi no kion wa joushou suru ippou da.

Due to global warming, temperatures in various regions are only continuing to rise.

Compare

～一方だ vs ～一方で

Both use 一方. ～一方だ ends the sentence and says a change keeps going in one direction. ～一方で joins two clauses: “while A, on the other hand B”.

  • ～一方だ, keeps -ing

    客きゃくは増ふえる一方いっぽうだ。

    kyaku wa fueru ippou da.

    The customers just keep increasing.

    A continuing change; the sentence ends.

  • ～一方で, while, on the other hand

    客きゃくは増ふえる一方いっぽうで、店員てんいんは減へっている。

    kyaku wa fueru ippou de, ten'in wa hette iru.

    While customers keep increasing, the number of staff is going down.

    Two things side by side.

Examples

ネットショッピングの利用者りようしゃの数かずは、年々ねんねん伸のびる一方いっぽうだ。

netto shoppingu no riyousha no kazu wa, nennen nobiru ippou da.

The number of people who shop online keeps growing year after year.

この十年じゅうねんで、町まちの小ちいさな本屋ほんやは減へる一方いっぽうだ。

kono juunen de, machi no chiisana hon’ya wa heru ippou da.

Over these ten years, the town’s small bookshops have kept on decreasing.

SNSで紹介しょうかいされてから、この店みせの人気にんきは高たかまる一方いっぽうだ。

esu enu esu de shoukai sarete kara, kono mise no ninki wa takamaru ippou da.

Since it was featured on social media, this shop’s popularity has kept on rising.

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