ないうちに | Grammar

Structure

[verb ない-form] + うちに

[v5] → ない + うちに
[v1] → ない + うちに
[する → しない] + うちに
[来る → こない] + うちに

Description

The grammar structure ないうちに is used to express doing something before a certain change or event occurs. It combines the negative form of a verb with うちに ("while"), literally meaning "while something has not yet happened." The emphasis is on taking action before it's too late – before the situation changes in an undesirable way.

Before something happens

The most common use is to urge or suggest that an action be taken before an unwanted change takes place.

。

Let's go home before it gets dark.

。

I brought in the laundry before it rained.

The speaker implies that once the change occurs, it will be too late or inconvenient.

While something hasn't happened yet

ないうちに can also describe something that happened while a state had not yet changed – often something unexpected or unintentional.

。

I fell asleep without realizing it.

。

Before I knew it, time had passed.

In these cases, the nuance is closer to "without (one's awareness)" or "before one knew it."

Comparison with 前に

While まえに前に simply means "before" in a temporal sense, ないうちに adds a sense of urgency or a window of opportunity closing. It implies that there is a reason to act now – before the situation changes.

。

Let me write it down before I forget.

Compare: わすれる忘れるまえに前にめもメモしておこう – similar meaning, but ないうちに emphasizes the narrowing window more strongly.

Examples

。

Let's go home before it gets dark.

。

Please write it down before you forget.

。

Let's go shopping before it rains.

。

Eat it before it gets cold.

。

Before I knew it, the cherry blossoms had fallen.

。

Let's finish the preparations before anyone comes.

。

I missed my stop without even realizing it.

。

I cleaned while the children were still asleep.

。

You should buy the tickets before the price goes up.

。

Let's go down the mountain before the sun sets.

。

You might make a lot of mistakes while you're still not used to it.

。

Let's get into the restaurant before it gets crowded.

References

ないうちにBunpro