모두 versus 다 as an adverb. What is the difference in this practical example?

Question

Is there any difference in nuance between 모두 and 다? Are there times when it is more appropriate to use one over the other?

Here is a practical example I have been looking at:

재료는 모두 준비되어 있습니다.

versus

재료는 다 준비되어 있습니다.

Answer 1

In many cases they are interchangeable, but I think 모두 has a tendency to describe multiple distinct items.

So, for example, (A) below is more likely to mean "Everybody drank water," so that it describes multiple distinct persons. (B) is more likely to mean "[Somebody] drank all the water." (However, as I said, they are just tendencies and I feel that both sentences can be used for both situations.)

(A) 물을 모두 마셨어요.

(B) 물을 다 마셨어요.

Also, 다 frequently means "fully; to the full possible extent; (colloquially) almost". When used this way, usually, it cannot be replaced by 모두. For example,

부산까지 다 왔습니다. = We're (almost) arriving at Busan.

부산까지 모두 왔습니다. = Everyone arrived at Busan.

컴퓨터가 다/완전히 맛이 갔네요. = The computer is totally broken.

컴퓨터가 모두 맛이 갔네요. = All the computers are broken.

Answer 2

In counting, 모두, 다 as a adverb have almost same meaning (cf. 2)). But 모두 can be a pronoun and 다 have more wide usage as a adverb in estimating degree.

1) 모두 is pronoun

누가 대표가 될지는 우리반 모두의 관심거리다

It is our interest that someone will be a representative.

누가 대표가 될지는 우리반 다의 관심거리다 (X)

2) When things satisfying given condition can be counted at that time, then we can use both, i.e., 모두, 다.

회원들은 다 참석할 것이다.

Members all will participate

재료는 다 (=모두 다=모두) 준비되어 있습니다.

All which is needed are prepared.

다 이해 할 수 있다.

I can understand all.

3) In further, 다 indicates a completion of given one project.

목적지에 다 왔다.

We come near at the goal place.

오늘 일은 다 끝났다.

Work for today is completely done.

@@ If we planed two works, for instance, swimming and buying a pencil, then we can use the following ? 너 오늘 일 모두 마쳤니 ? Did you finish today's two works ?

여름이 다 갔다.

Summer is gone almost.

우수운 꼴도 다 보겠네.

I am underestimated so that I am not happy.

비가 오니 내일 소풍은 다 갔군

Because it rains, so tomorrow's picnic may not be fun.