つい (tsui) – Meaning & Usage

つい means accidentally; without meaning to. It is a JLPT N3 grammar pattern used to show an action happened unintentionally or despite knowing better.

If you want to express that you did something on impulse — even though you knew you shouldn’t — つい is the pattern you need.

つい captures that moment when impulse wins over judgment.

What does つい mean?

Use つい when you want to show an action happened unintentionally or despite knowing better.

Natural translations include:

accidentally; without meaning to

Notice whether the speaker regrets the action or simply drifted into it, then choose the English phrase that fits.

How to form つい

つい + Verbてしまう / Verbた

Examples of the pattern:

つい食べてしまう
つい忘れた
つい言ってしまった

The form after つい matters. In JLPT questions, wrong choices often attach つい to the dictionary form or other incorrect patterns.

When is つい used?

Use つい in situations like:

describing an unintentional action you regret or know you should avoid
reacting to sudden impulse or temptation
making natural Japanese sentences that explain a slip-up

Tone and register:

neutral — used in both spoken and written Japanese
common in JLPT N3 reading passages, grammar questions, and everyday conversation

つい example sentences

ダイエット中(ちゅう)なのに、ついケーキを食(た)べてしまった。

Even though I am on a diet, I accidentally ate cake.

秘密(ひみつ)なのに、つい話(はな)してしまった。

It was a secret, but I accidentally told someone.

忙(いそが)しくて、つい約束(やくそく)を忘(わす)れてしまった。

I was busy and unintentionally forgot the promise.

面白(おもしろ)くて、つい笑(わら)ってしまった。

It was funny, and I could not help laughing.

安(やす)かったので、つい買(か)ってしまった。

It was cheap, so I bought it without thinking.

After reading each sentence, ask what job つい is doing: the speaker acted on impulse and immediately recognizes it as unintentional.

Nuance of つい

The key nuance is a natural way to express “accidentally; without meaning to” with the right context and tone.

This matters because つい does more than match a single English phrase. It shows how the speaker frames the action as a momentary lapse — often one they regret or find hard to control.

For example:

In context, it sounds natural when the surrounding sentence supports a feeling of impulse or regret.
Compared with うっかり, it carries a different focus: つい emphasizes acting despite yourself, while うっかり emphasizes carelessness.

つい vs うっかり

Both つい and うっかり can describe accidental actions, but they are different.

つい

accidentally; without meaning to

Use when impulse or temptation overrides your better judgment.

ダイエット中(ちゅう)なのに、ついケーキを食(た)べてしまった。

Even though I'm on a diet, I couldn't help eating cake.

うっかり

carelessly; by accident

Use when the action results from inattention or forgetting.

ダイエット中(ちゅう)なのに、うっかりケーキを食(た)べてしまった。

(Less natural — implies you forgot you were dieting, not that you gave in to temptation.)

If both words seem possible, check the cause. Did you give in to an urge (つい), or did you stop paying attention (うっかり)?

Common mistakes with つい

❌ つい食べる

✅ つい食べてしまう / つい食べた

Attach the て-form or past tense to つい. The dictionary form does not follow this pattern.

❌ ダイエット中なのに、うっかりケーキを食べてしまった。

✅ ダイエット中なのに、ついケーキを食べてしまった。

For impulse or temptation, use つい. うっかり implies carelessness, not acting despite yourself.

❌ Translating つい word-for-word without reading the full sentence

✅ Read the context to confirm the action is unintentional or against the speaker's better judgment.

A helpful practice method is to write one sentence with つい, then rewrite it with うっかり.

Is つい on the JLPT?

Yes. つい is commonly taught as JLPT N3 grammar.

That means you should be able to recognize it in reading, understand its nuance in context, and use it in simple original sentences.

Recognize つい + Verbてしまう / Verbた in test sentences
Distinguish it from うっかり in reading passages
Identify the speaker's regret or impulse in context questions

Practice questions for つい

1 Write one sentence using つい. N3

2 Contrast つい with うっかり in your own example. N3

3 Make a JLPT-style sentence where the context makes the meaning clear. N3

Learning path for つい

To learn つい efficiently, review plain emotion verbs first, then practice patterns where the feeling is automatic, impulsive, or hard to control.

1 First, make sure you can form つい with Verbてしまう and Verbた without looking at the pattern chart.

2 Next, compare it with てしょうがない・てしかたがない and どうしても. These patterns are close enough that choosing between them helps you understand the nuance of impulse and necessity.

3 Finally, write sentences about surprise, regret, urges, and strong reactions; then check whether replacing つい with ずにはいられない changes the meaning.

てしょうがない・てしかたがない — because it also expresses spontaneous feelings, urges, or emotional reactions.
どうしても — because it also expresses strong impulse or unavoidable desire.
ずにはいられない — because it also describes actions driven by irresistible urge.
ふと — because it also describes sudden, unintentional actions.

Learn つい with Hane

If you want to review つい together with the related patterns above, Hane helps you connect grammar, kanji, and vocabulary in short, focused sessions.

Browse more lessons here:

FAQ about つい

What does つい (tsui) mean in Japanese?

つい (tsui) means “accidentally; without meaning to”. It is JLPT N3 grammar. Use つい when you want to show an action happened unintentionally or despite knowing better.

How do you form つい (tsui)?