What does ～一方だ mean? Japanese grammar N2

Forming it

How to use it

A situation keeps changing in a SINGLE direction, without reversing. Mostly a negative direction.

• 「Vる一方だ」 = increasingly…: 「この町の人口は減る一方だ」.
• Only combines with verbs of CHANGE (増える・減る・悪化する・上がる); does not combine with action verbs.
• Different from 「つつある」 (transitioning to a new state, neutral): 「一方だ」 emphasizes a continuing trend that is usually negative.

Examples

• この町(まち)の人口(じんこう)は減(へ)る一方(いっぽう)だ。

  The population of this town keeps declining.

• 物価(ぶっか)は上(あ)がる一方(いっぽう)で、生活(せいかつ)が苦(くる)しくなってきた。

  Prices keep rising, and life is getting harder.

Keep in mind

• Only combines with verbs of change, dictionary form.
• Usually carries a negative nuance.

Common mistakes

• Wrong毎日(まいにち)勉強(べんきょう)する一方(いっぽう)だ。

  All he does is study.

  Correct毎日(まいにち)勉強(べんきょう)するばかりだ。

  「一方だ」 only combines with verbs of change, not ordinary action verbs.

• Wrong人口(じんこう)は減(へ)った一方(いっぽう)だ。

  The population keeps declining.

  Correct人口(じんこう)は減(へ)る一方(いっぽう)だ。

  Connects to the dictionary form.

Exam tips

• 「一方だ」 = increasingly (one direction, usually negative); only verbs of change.

Related patterns

• ～つつある
• ～ばかりだ
• ～ていく