When studying Japanese, you may come across sentences like these:
“I try to study Japanese every day.”
“I decided to study Japanese every day.”
At first glance, both seem to express the speaker’s intention, so the difference can feel unclear.
However, these two expressions are used in clearly different ways.
“ようにする” expresses a conscious effort to keep doing something.
“ことにする” expresses a personal decision.
Once you understand this difference, your Japanese will sound much more natural.
“ようにする” expresses conscious ongoing effort
“ようにする” has the nuance of making an effort to continue an action or maintain a certain state.
What matters here is not just making a decision at one moment, but continuing to work toward it afterward.
Examples
I try to review kanji every morning.
I try not to look at my phone too much at night.
I started trying to take notes so I would not forget.
In these examples, the feeling is: “I am careful to do this” or “I am making an effort to keep doing this.”
Even if you are not perfect at it yet, that is fine.
The key point is that you are moving in that direction.
In other words, “ようにする” carries the image of habit-building and continuity.
“ことにする” expresses making a decision
On the other hand, “ことにする” is used when the speaker decides something by their own will.
Here, the main focus is the fact that a decision has been made.
Examples
I’ll go home by taxi today.
I decided to increase my Japanese lessons starting next month.
I decided to take the JLPT N2 this year.
With this expression, the speaker’s intention comes forward as: “This is what I decided.”
It can be used for a one-time decision, and it can also be used when deciding on a future plan.
Let’s compare the two
Now look at these two sentences:
I decided to read Japanese news every day.
I try to read Japanese news every day.
The first sentence focuses on the decision itself.
The second sentence focuses on the effort to continue doing it in real life.
So the difference can be summarized like this:
“ことにする” = decision
“ようにする” = conscious effort for continuity
They may look similar, but they describe different situations.
A point that learners often find confusing
Many learners tend to feel that “deciding to do something” and “continuing to do something” are basically the same.
For example:
I have decided to eat vegetables.
I try to eat vegetables.
At first, both may seem possible. But when talking about a daily habit, the second one often sounds more natural.
That is because “eating vegetables” is often discussed as a lifestyle habit, and “ようにする” matches that nuance of continued awareness and effort.
On the other hand, this sentence can sound slightly unnatural:
I’ll try to go home early tomorrow.
If you want to express a decision made at that moment, it is more natural to say:
I’ve decided to go home early tomorrow.
How to choose when you are unsure
If you are not sure which one to use, this way of thinking helps:
Use “ことにする” when you are talking about something you decide for yourself at that moment.
Use “ようにする” when you are talking about something you are consciously trying to continue.
Just keeping this idea in mind makes the distinction much easier.
Conclusion
Both “ようにする” and “ことにする” include the speaker’s intention, but the center of meaning is not the same.
“ようにする” expresses habit-building and continued effort.
“ことにする” expresses making a decision for yourself.
Once you can clearly grasp this difference, both your conversation and your writing will become more natural and more accurate.
The more similar two expressions look, the more important it is to understand their difference.
That is why organizing these subtle nuances one by one is one of the fastest ways to improve your Japanese.
If you want to master these fine differences through example sentences and practice, visit Rapid Japanese Training. It is designed to help you study grammar, vocabulary, reading, and listening efficiently.
