amuri yeonseuphaedo daesaneun eoryeowo.

It means no matter how much ... or even if ... a lot.

So 아무리 연습해도 gives the idea of:

• no matter how much I practice
• even after practicing a lot
• however much I practice

This pattern is very common in Korean:

• 아무리 먹어도 배고파.
  = No matter how much I eat, I’m hungry.
• 아무리 생각해도 모르겠어.
  = No matter how much I think about it, I don’t know.

So in your sentence, it sets up a contrast: practice happens a lot, but the result is still the same.

연습해도 comes from 연습하다 + -아/어도.

Step by step:

• 연습하다 = to practice
• 연습해 = practice / practicing
• 연습해도 = even if one practices / even though one practices

With 하다 verbs, -아/어도 becomes 해도:

• 공부하다 → 공부해도
• 일하다 → 일해도
• 연습하다 → 연습해도

So 연습해도 by itself means even if I practice or though I practice, and with 아무리, it becomes stronger: no matter how much I practice.

대사 usually means lines or dialogue, especially in a script, movie, drama, play, or performance.

So this is not just general speech or talking. It specifically suggests words that someone has to say as part of a role or performance.

Compare:

• 말 = words, speech, what someone says in general
• 이야기 = story, talk, conversation
• 대사 = scripted lines / dialogue

So if someone is acting, rehearsing, dubbing, or practicing a performance, 대사 is the natural word.

The -는 is the topic marker.

So 대사는 어려워 is like saying:

• As for the lines, they’re hard
• The lines, though, are hard

This often gives a slight sense of focus or contrast. It can imply something like:

• maybe other things are okay, but the lines are hard
• we are now talking specifically about the lines

If you said 대사가 어려워, that would sound more like a neutral statement of fact: the lines are hard.

Both can work, but 대사는 feels a little more topical or contrastive.

Because Korean often leaves out subjects when they are already understood from context.

In English, you usually need to say I, they, it, and so on. In Korean, if the listener already knows who is being talked about, the subject is often omitted.

So this sentence could mean:

• No matter how much I practice, the lines are hard
• No matter how much we practice, the lines are hard
• No matter how much he/she practices, the lines are hard

The exact subject depends on context.

This is very normal Korean, not an incomplete sentence.

Because 어렵다 is a ㅂ-irregular adjective.

Here is what happens:

• dictionary form: 어렵다
• stem: 어렵-
• before a vowel-like ending such as -어, the ㅂ changes
• the result becomes 어려워

So:

• 어렵다 → 어려워
• not 어렵어

Other similar examples:

• 덥다 → 더워
• 춥다 → 추워
• 맵다 → 매워

This is a very common pattern, so it is worth memorizing.

어려워 is a casual, non-polite form.

Related forms are:

• 어렵다 = dictionary form / plain style
• 어려워 = casual spoken form
• 어려워요 = polite spoken form
• 어렵습니다 = formal polite form

So the sentence could be adjusted depending on situation:

• 아무리 연습해도 대사는 어려워.
  casual
• 아무리 연습해도 대사는 어려워요.
  polite
• 아무리 연습해도 대사는 어렵습니다.
  formal

Korean nouns often do not explicitly show singular vs. plural.

So 대사 can mean:

• a line
• lines
• dialogue as a general mass idea

In this sentence, English will often translate it as the lines because that sounds natural in context, but Korean itself does not force that choice.

You understand the number from context, not from the noun form alone.

Not necessarily. The sentence only says that the lines are difficult.

That could mean different things, such as:

• hard to memorize
• hard to pronounce
• hard to deliver naturally
• hard to act with the right emotion
• hard to say smoothly

Korean often leaves this kind of detail unstated unless it matters. So 어려워 is broad: it just tells you that the lines are difficult in some relevant way.

You could say 많이 연습해도, but it is not exactly the same.

• 많이 연습해도 = even if I practice a lot
• 아무리 연습해도 = no matter how much I practice

아무리 sounds stronger and more emphatic. It suggests that the amount of practice does not change the outcome at all.

So:

• 많이 연습해도 대사는 어려워.
  Even if I practice a lot, the lines are hard.
• 아무리 연습해도 대사는 어려워.
  No matter how much I practice, the lines are hard.

The second one feels more like frustration or helplessness.