を境に【をさかいに】

since, from then on, after, ever since, turning point, with ~ as the boundary

AI-generated

Structure

[noun] + を境に [noun] + を境にして

Description

を境に marks a turning point: before the event or date in front of it things were one way, and after it they were another. It goes straight after a noun – an event, a date, an age – and さかい境 itself means "boundary". The second half says what changed.

、。

My life changed dramatically after getting married.

、。

After that accident, his personality changed.

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Since turning 30, my physical strength has been declining.

Because the pattern divides time in two, the second half describes a change that lasts: a verb like かわる変わる, 〜～ようになる, 〜～なくなる, or 〜～てくる. A single event that happened once does not fit.

、。

Since that incident, I stopped keeping in touch with him.

を境にして means the same.

、。

After the earthquake disaster, awareness of disaster prevention increased.

を境に or をきっかけに

names the trigger that set something off, and what follows can be a single event. を境に names the line between a before and an after, and what follows is the new state.

、。

Studying abroad got me started on Japanese.

、。

After studying abroad, her way of thinking completely changed.

A boundary in space

The same phrase can mark a line on the ground – a river, a road, a mountain range – with something different on either side.

、。

The dialect is different east and west of this river.

Examples

、。

After my father's death, the family's relationships changed.

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Since that incident, I stopped keeping in touch with him.

、。

Since turning 30, my physical strength has been declining.

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Since moving, I've become a morning person.

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From that game onward, the team went on a winning streak.

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After studying abroad, her way of thinking completely changed.

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After the burst of the economic bubble, Japan's economy entered a long period of stagnation.

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After being hospitalized, I quit drinking.

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After that incident, security was strengthened.

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Since retiring, I started spending my time on hobbies.

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Since COVID, remote work became common.

を前提として / を前提に

を押して / を押し切って