to notice; to realize (に気がつく) – Japanese Grammar に気がつく (ni ki ga tsuku)

Q: What JLPT level is に気がつく?

JLPT N4 — Upper-Beginner · Forming complex sentences

Q: How do you use に気がつく in a sentence?

Attach に気がつく to the appropriate verb or noun form. To notice; to realize

Q: Is に気がつく formal or casual Japanese?

に気がつく can be used in both casual conversation and polite speech depending on context.

に気がつく

N4 GRAMMAR ⏱ 0s study 📖 0 today

ni ki ga tsuku

to notice; to realize

も mo てくれる te kureru でも demo やっと yatto ぜひ zehi そうに・そうな sou ni / sou na ようにする you ni suru ことができる koto ga dekiru 他動詞 & 自動詞 tadoushi & jidoushi させる saseru ているところ teiru tokoro でございます de gozaimasu てよかった te yokatta たがる tagaru まま mama こと koto てやる te yaru かどうか ka dou ka って tte おきに oki ni も mo てくれる te kureru でも demo やっと yatto ぜひ zehi そうに・そうな sou ni / sou na ようにする you ni suru ことができる koto ga dekiru 他動詞 & 自動詞 tadoushi & jidoushi させる saseru ているところ teiru tokoro でございます de gozaimasu てよかった te yokatta たがる tagaru まま mama こと koto てやる te yaru かどうか ka dou ka って tte おきに oki ni

🃏 Flashcard

に気がつく

ni ki ga tsuku

Tap to reveal usage

to notice; to realize

Tap to test your recall · +10 XP

📊 Pattern Stats

JLPT Level N4

Upper-Beginner · Forming complex sentences

Reading ni ki ga tsuku

Post ID 50738

Patterns today 0

0 / 10 daily goal

📝 Usage Notes

to notice; to realize

📖 How to use it

This pattern expresses the act of noticing or realizing something, often something that was previously overlooked.

Attaches to Attach to a noun (thing noticed) followed by に気がつく. The noun can be a concrete object, a situation, or a nominalized verb phrase (e.g., 間違いに気がつく).

に気がつく (ni ki ga tsuku) means 'to notice' or 'to realize'. It is used when you become aware of something through your senses or through thought. The thing noticed is marked by に. For example, if you notice a mistake in your homework, you say 宿題の間違いに気がつきました. If you realize you forgot your keys, you say 鍵を忘れたことに気がつきました. The pattern is neutral and can be used in both speaking and writing. It is often used with past tense to describe a realization that happened at a specific moment. Note that the subject is usually the person who notices, and the particle が in 気がつく is part of the idiom, so に marks what is noticed. This is a set phrase; you cannot replace が with を.

電車を降りてから、傘を忘れたことに気がついた。

Densha o orite kara, kasa o wasureta koto ni ki ga tsuita.

After getting off the train, I realized I had forgotten my umbrella.

彼女は私の新しい髪型に気がつかなかった。

Kanojo wa watashi no atarashii kamigata ni ki ga tsukanakatta.

She didn't notice my new hairstyle.

この文の間違いに気がつきましたか。

Kono bun no machigai ni ki ga tsukimashita ka.

Did you notice the mistake in this sentence?

Not に気づく (ni kidzuku) に気づく is a more direct verb form and is used in similar situations, but に気がつく is a set phrase with が. In casual speech, you might hear 気づく more often. Both mean 'to notice', but に気がつく is slightly more formal and emphasizes the moment of realization. Also, に気がつく can be used with に, but 気づく can also take を in some cases? Actually, both take に. The difference is just stylistic; 気づく is shorter and more common in conversation.

Register This pattern is neutral and can be used in both polite and casual speech, though it is slightly more formal than just using 気づく. It is common in written narratives and everyday conversation.

🎯 Quick Quiz

What does this grammar pattern mean or do?

に気がつく

📚 How to Master This Pattern

🔊

Say It Aloud

Press Hear it and repeat に気がつく three times. Feel the rhythm — grammar patterns have a natural flow.

🃏

Flip Before Reading

Always try to recall the usage before flipping the card. Struggle = learning. Every failed recall makes the next one stick harder.

✍️

Write Two Sentences

Compose two original sentences using に気がつく. One about yourself, one about something you see right now.

⏰

Spaced Review

Save this pattern and revisit at 10 min, 1 day, 3 days. Production (writing) beats recognition for grammar.

🔗 More JLPT N4 Patterns

to look; to seem; to appear

❓ Frequently Asked Questions

What does the grammar pattern に気がつく mean? ▼

To notice; to realize

What JLPT level is に気がつく? ▼

Nihoner currently groups this pattern under JLPT N4 — Upper-Beginner · Forming complex sentences. Use the level label as study guidance rather than a prediction of what will appear on an exam.

How do you use に気がつく in a sentence? ▼

Attach に気がつく (ni ki ga tsuku) to the appropriate verb or noun form as described in the usage notes. Then try writing two original sentences — one about yourself and one about something around you.

Is に気がつく formal or casual Japanese? ▼

に気がつく is used in both casual and polite contexts. It appears frequently in everyday conversation, textbooks, and simple written materials.

How can I remember に気がつく long-term? ▼

Use the flashcard on this page for active recall — see the pattern, reconstruct the usage from memory, then flip. Follow with the 4-choice quiz to distinguish it from similar patterns. Review later the same day and again over the following days. Writing original sentences can help you practise using the pattern in context.