seonsaengnimi yeonseuphalsurok bareumi johajindaeyo.

-ㄹ수록 / -을수록 means the more..., as ... more and more, or the more A, the more B.

So:

• 연습할수록 = the more you practice
• 연습할수록 발음이 좋아진대요 = They say pronunciation gets better the more you practice

This pattern usually links two changes together:

• 많이 볼수록 좋아요 = The more I see it, the more I like it.
• 공부할수록 어려워요 = The more I study, the harder it gets.

Because the pattern attaches to the verb stem.

• Dictionary form: 연습하다
• Stem: 연습하-
• Add -ㄹ수록
• Result: 연습할수록

This is normal for 하다 verbs:

• 공부하다 → 공부할수록
• 운동하다 → 운동할수록
• 연습하다 → 연습할수록

So 할수록 here is not a separate word meaning can do. It is just 하다 combined with the grammar pattern -ㄹ수록.

Because 좋아지다 is an intransitive verb: it means to become better / to improve. The thing that improves is the subject, not the object.

So:

• 발음이 좋아지다 = pronunciation improves
• not 발음을 좋아지다

Compare:

• 발음을 연습하다 = practice pronunciation
  Here 발음 is the object, so 을/를 is used.
• 발음이 좋아지다 = pronunciation improves
  Here 발음 is the subject, so 이/가 is used.

• 좋다 = to be good
• 좋아지다 = to become good / to get better / to improve

So:

• 발음이 좋다 = the pronunciation is good
• 발음이 좋아지다 = the pronunciation gets better

In this sentence, the idea is not just that the pronunciation is good, but that it improves as practice increases.

좋아진대요 is a conversational reported-speech form. It comes from 좋아진다고 해요.

So it means something like:

• (someone says) it gets better
• they say it gets better
• I hear it gets better

Breaking it down:

• 좋아진다 = it gets better
• 좋아진다고 해요 = they say it gets better
• 좋아진대요 = shortened conversational form of that

This ending is very common in spoken Korean.

It is basically a reported present/general statement.

So 좋아진대요 usually means:

• they say it gets better
• they say it will get better
• I hear it improves

In English, the best translation depends on context. Korean often uses this form for general truths or repeated results.

For comparison:

• 좋아진대요 = they say it gets better
• 좋아졌대요 = they say it got better / has gotten better

This is something many learners notice. Korean can allow a kind of double-subject structure.

In a sentence like this, the first noun can set the overall person/topic, and the second noun can be the thing that actually has the property or changes.

So:

• 선생님이 발음이 좋다 can mean
• The teacher has good pronunciation
• more literally, As for the teacher, the pronunciation is good

In the same way:

• 선생님이 연습할수록 발음이 좋아진대요 can be understood as
• The teacher’s pronunciation gets better the more he/she practices

This structure is normal in Korean, even though it feels unusual from an English point of view.

It can actually be ambiguous without context.

Possible readings include:

1. Double-subject reading
   선생님이 ... 발음이 좋아진대요
   = The teacher’s pronunciation gets better...

2. Source-of-report reading
   = The teacher says that pronunciation gets better...

Context usually tells you which one is intended.

If you want to make the teacher says... clearer, Korean often uses something more explicit, such as:

• 선생님이 말씀하시길...
• 선생님께서 ... 하셨어요
• 선생님이 그러시는데...

So if you felt that 선생님이 could be interpreted in more than one way, that is a very reasonable question.

That depends on how the sentence is being interpreted.

If it means:

• The more you practice, the better your pronunciation gets

then the subject is understood from context, and Korean simply leaves it out.

If it means:

• The teacher’s pronunciation gets better the more the teacher practices

then 선생님이 is connected to the practicing as well.

Korean often omits subjects when they are clear from the situation, so English speakers often feel there is missing information, even though Korean sounds natural that way.

Yes, and it would be natural, but the nuance is a little different.

• 연습하면 발음이 좋아져요 = If/when you practice, your pronunciation improves.
• 연습할수록 발음이 좋아져요 = The more you practice, the better your pronunciation gets.

So:

• -면 focuses on a condition: if you practice
• -ㄹ수록 focuses on gradual increase: the more you practice

If you want the idea of increasing improvement, -ㄹ수록 is the better choice.

It is polite, but conversational.

• The -요 ending makes it polite.
• The -대요 form is common in everyday speech when reporting what someone said or what you heard.

So it is less formal than:

• 좋아진다고 합니다

and more natural in ordinary conversation than very formal written-style Korean.

If you wanted a more formal version, you could say:

• 연습할수록 발음이 좋아진다고 해요
• 연습할수록 발음이 좋아진다고 합니다

If the teacher is the person being respectfully quoted, you might also hear:

• 선생님께서 연습할수록 발음이 좋아진다고 하셨어요