Today, I am going to share the homework correction from my JLPT N4 course!
The student’s sentence is not correct. Can you find the mistake?

 

[Student’s sentence]

字がよく見えるために、めがねを買いました。

*じがよくみえるために、めがねをかいました。

 

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[My correction]

字がよく見えるために、めがねを買いました。
→字がよく見えるように、めがねを買いました。
I bought glasses so that I could see the letters better.

 

ために indicates the objective of an action, so a volitional verb should come before ために. However, 見える (to be visible) is not something you do; therefore, you cannot use ために with 見える.
On the other hand, ように expresses the expectation of realizing an objective, so non-volitional verbs like 見える can be used with ように.

 

e.g.
うまく話(はな)すために、日本語(にほんご)を勉強(べんきょう)しています。
I am studying Japanese in order to speak well.

Volitional verb = what you will do.
What you will do is “speak（話す）”, but not “can speak（話せる potential-form）”.
So the potential-form is not used before ために, but the dictionary-form as an action.

 

うまく話せるように、日本語を勉強しています。
I am studying Japanese so that I can speak well.

ように expresses aims by describing ideal situations.
Since it represents a state, “can speak（話せる potential-form）” is used instead of the action “speak (話す)”.

 

I hope my explanation helps you. 😊

 

In the JLPT course, all lessons come with homework. If you submit your homework, I will reply with corrections.
I can break down the Japanese grammar and point out mistakes, explaining the structure and nuances of Japanese in an easy-to-understand way.
You can also ask me any questions in as much detail as you want. I will teach you until you get it!