Examples
Meaning
〜ようにする means to make an effort or make a habit of doing something. 〜ようになる means to become able to do something or to come to do something.
Formation
Both patterns often follow the dictionary form or negative form of a verb. 〜ようになる also commonly follows the potential form, such as 読めるようになる.
Usage
Use 〜ようにする when you are still trying or setting a rule. Use 〜ようになる when the change has already happened or is expected to happen as a result.
Nuance
The contrast is effort versus result. 〜ようにする is active and intentional. 〜ようになる is change-focused and often gradual.
Comparison
毎日単語を覚えるようにしています means I try to memorize words every day. 新しい単語を覚えられるようになりました means I have become able to memorize new words.
Common Mistakes
A common mistake is using 〜ようになる when the speaker only means they are trying. If the result is not achieved yet, 〜ようにする or 〜ようにしている is usually better.
Related Grammar
〜ようにする
〜ようにする expresses making an effort, setting a habit, or trying to make sure something happens or does not happen.
〜ようになる
〜ようになる expresses a change into a new state, habit, or ability, especially something that has become possible over time.
〜ことにする
〜ことにする means to decide to do or not do something. It emphasizes the speaker's or subject's own decision.
〜ようになる・〜ことになるの違い
This page compares 〜ようになる and 〜ことになる, two patterns that can both describe change but focus on different kinds of change.