By adding “~았/었으면 좋겠다” to the end of a verb/adjective, you can create the meaning of “I hope” or “I wish.” This is one of the grammatical principles where I suggest looking at the whole thing as one and not trying to break it up into separate pieces. Let’s look at one simple example and then talk about it:
비가 안 왔으면 좋겠어요 = I hope it doesn’t rain
Notice that the past tense conjugation is used before “~면” and the future tense conjugation is used on “좋다.” Despite the use of these past and future conjugations within it, the speaker is indicating that he/she is currently hoping for that situation to occur – whether that situation be in the present or in the future. Below are many other examples:
양이 많았으면 좋겠어요 = I hope there is a lot (I hope the amount is a lot)
비가 안 왔으면 좋겠어요 = I hope it doesn’t rain
내일 일이 없었으면 좋겠어요 = I wish I didn’t have work tomorrow
그 말을 사전에 했으면 좋겠어요 = I wish you told me that beforehand
나를 무조건 사랑했으면 좋겠어 = I wish you loved me unconditionally (no matter what)
삶을 한가롭게 살았으면 좋겠어 = I wish I could live life freely/leisurely
집에 가서 집이 청결했으면 좋겠어요 = I hope the house will be clean when I go home
엄마가 저를 데리러 왔으면 좋겠어요 = I wish mom would come to pick me up
우리는 그 여자랑 같이 갔으면 좋겠어요 = I hope we go together with that girl
그것 때문에 나를 해고하지 않았으면 좋겠다 = I wish/hope you don’t fire me because of that
저를 의도적으로 피하려고 안 했으면 좋겠어요 = I wish you didn’t deliberately try to avoid me
내일 경기에서 우리 팀 모두가 최선을 다하면 좋겠어 = Tomorrow, I hope everybody on our team tries their best
You also may see other words (usually 하다 or 바라다) used instead of 좋다. For example:
우리가 곧 만났으면 해
우리가 곧 만났으면 바래요
= I wish we could meet soon, it would be nice if we could meet soon
It is also possible for ~(으)면 to be attached to a word without being conjugated to the past tense. For example:
비가 안 왔으면 좋겠어요
비가 안 오면 좋겠어요
= I hope it doesn’t rain
If you ask a Korean person, they will say that the two examples above have the same meaning. Both of them are indicating “hope” or a “wish” in the present tense. I’ve never read a concrete explanation as to why the two examples above have the same meaning. Korean people just tend to use the first example (using “~았/었으면”) when indicating one’s hope or wish.
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That being said, I would like to provide my own take on this topic. This is based on nothing but my own feelings. I’ve tried to discuss this with Korean grammar teachers, and I’ve tried to research it, but they all say that both examples are identical, and that they would be more likely to say “ ~았/었으면”)
I like to think that using “~았/었으면 좋겠다” is a grammatical principle itself, and something that can’t be separated into pieces. The whole construction indicates one’s “wish.” For example:
비가 안 왔으면 좋겠어요 = I hope it doesn’t rain
However, I like to think that using ~(으)면 좋겠다 is something that can be separated into individual grammatical pieces. The use of ~(으)면, meaning “if” or “when” (from Lesson 43) followed by “좋겠다” indicating that “it will be good.” We can look at these examples as sentences that are made up of its individual parts. For example:
비가 안 오면 좋겠어요 = It would be good if it doesn’t rain
The thing is, both sentences (in English and Korean) – whether you think of “~았/었으면” as a single unit or see “~(으)면 좋겠다” as individual pieces – express the same meaning.