While, whereas: 〜一方（で）
plain form (N である, な-adj な／である) + 一方（で）; at the start: 一方、
Plain form + 一方（で）: “while, whereas, on the other hand, while also”. A contrast between two facts, even with two subjects; distinguish it from 一方だ (“just keeps”).
In short
〜一方（で） sets two facts side by side to contrast them: “while, whereas, on the other hand”. The two facts can concern two different subjects (cities / villages) or two roles of the same person (“while also”). Written register, the press, presentations.
- 都市の人口が増える一方で、村の人口は減っている。としのじんこうがふえるいっぽうで、むらのじんこうはへっている。While the population of cities is growing, that of villages is shrinking.
- 彼は会社員として働く一方で、週末は小説を書いている。かれはかいしゃいんとしてはたらくいっぽうで、しゅうまつはしょうせつをかいている。While working as an office employee, he writes novels at weekends.
- 輸出は増えた。一方、輸入は減った。ゆしゅつはふえた。いっぽう、ゆにゅうはへった。Exports rose. Imports, on the other hand, fell.
The basics
一方 means “one side”. 〜一方で describes a first side, then moves to the other: you set two realities next to each other to bring out the contrast. It's the “while” or “whereas” of articles and presentations.
With a single person, it expresses two activities or roles carried on in parallel: “while also…, he…”.
While the population of cities is growing, that of villages is shrinking.
- noun
- verb
- grammatical form
- ごみを減らす人が増える一方で、ルールを守らない人もまだ多い。ごみをへらすひとがふえるいっぽうで、るーるをまもらないひともまだおおい。While more and more people are cutting down on waste, many still don't follow the rules.
How to form it
一方（で） follows a plain form; with a な-adjective, な or である; with a noun, である. で is optional. At the start of a sentence, 一方、 (or その一方で) serves as a connector: “on the other hand, meanwhile”.
| Before | Example |
|---|---|
| Verb | 増える一方で |
| い-adj | 給料が高い一方で |
| な-adj | 便利な一方で |
| Noun | 学生である一方で |
| At the start | 一方、〜／その一方で、〜 |
- この町は観光客に人気がある。一方、住民は交通の問題に困っている。このまちはかんこうきゃくににんきがある。いっぽう、じゅうみんはこうつうのもんだいにこまっている。This town is popular with tourists. Residents, on the other hand, are struggling with traffic problems.
- 彼女は学生である一方で、小さな会社の社長でもある。かのじょはがくせいであるいっぽうで、ちいさなかいしゃのしゃちょうでもある。She's a student, and at the same time the president of a small company.
一方で or 一方だ?
一方だ (N3), at the end of a sentence, says a trend just keeps getting stronger: “just keeps…”. 一方で, mid-sentence, sets two facts side by side. Just one character changes, but the meaning is completely different.
| Sentence | Meaning |
|---|---|
| 値段は上がる一方だ | prices just keep going up |
| 値段が上がる一方で、給料は上がらない | prices are rising, while wages aren't |
- 森の面積は減る一方だ。もりのめんせきはへるいっぽうだ。Forest cover just keeps shrinking.
Compare with 反面
反面 stays with a single subject and its two sides (advantage / drawback). 一方で is broader: it accepts two different subjects, or two activities of one person. When there's only one subject, both are often possible.
- この仕事は楽しい反面、責任も重い。このしごとはたのしいはんめん、せきにんもおもい。This job is enjoyable, but it also comes with heavy responsibilities.
Common mistakes
- Mixing up 一方で (parallel) and 一方だ (“just keeps”, a trend): 上がる一方だ ≠ 上がる一方で.
- Using it for a simple sequence: “×朝ごはんを食べた一方で、学校に行った”. You need a contrast.
- Thinking 一方で and 反面 are always interchangeable: with two different subjects, only 一方で works.
7 exercises on this point
Particles to choose, sentences to put back in order, translations: marked straight away, then reviewed at the right time. This JLPT N2 point is on the Linimo Line (The environment) of the Nagoya lines.