ことにする
🃏 Flashcard
ことにする
koto ni suru
Tap to reveal usage
to decide on
N4
Tap to test your recall · +10 XP
📊 Pattern Stats
JLPT Level
N4
Upper-Beginner · Forming complex sentences
Reading
koto ni suru
Post ID
50719
Patterns today
0
0 / 10 daily goal
📝 Usage Notes
to decide on
📖 How to use it
Expresses a decision to do something, often a personal choice or resolution.
Attaches to
Attach to the dictionary (plain non-past) form of a verb: V-dictionary + ことにする.
This pattern means 'decide to do' and conveys a deliberate choice. It is often used for personal resolutions, plans, or rules you set for yourself. The nuance is that you actively make a decision, not that you are forced or it happens naturally. For example, when you decide to quit smoking, start studying, or change a habit, you use this.
In conversation, it is common to use the past tense ことにした for decisions already made. To express a habitual decision or a rule you follow, use the non-past form. Note that this pattern is different from ことになる, which means 'it has been decided (by others)' or 'it turns out that'.
毎日、日本語を勉強することにしました。
Mainichi, nihongo o benkyou suru koto ni shimashita.
I decided to study Japanese every day.
来週から、たばこをやめることにします。
Raishuu kara, tabako o yameru koto ni shimasu.
I've decided to quit smoking starting next week.
今晩は、外で食べることにしました。
Konban wa, soto de taberu koto ni shimashita.
I've decided to eat out tonight.
Not ことになる
ことにする is a personal decision made by the speaker; ことになる indicates a decision made by others or an external circumstance, often translated as 'it has been decided that' or 'it turns out that'.
Register
Neutral, used in both speaking and writing. In casual conversation, you may drop します and say ことにした, but the full form is always acceptable.
🎯 Quick Quiz
What does this grammar pattern mean or do?
ことにする
📚 How to Master This Pattern
Say It Aloud
Press Hear it and repeat ことにする 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 ことにする. 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
❓ Frequently Asked Questions
What does the grammar pattern ことにする mean?
▼
To decide on
What JLPT level is ことにする?
▼
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 ことにする in a sentence?
▼
Attach ことにする (koto ni suru) 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 ことにする formal or casual Japanese?
▼
ことにする is used in both casual and polite contexts. It appears frequently in everyday conversation, textbooks, and simple written materials.
How can I remember ことにする 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.