As of today, the vast majority of times I've come across せっかく, I've ended up understanding it in a somewhat blurry way and guessing the meaning from context. However, I would like to finally structure my knowledge about せっかく in my head, so I have tried to classify the different combinations of せっかく that I have come across so far by groups according to their meaning (in each group I have tried to put those combinations with the same meaning that are interchangeable with each other).
・ せっかく (just this word, with no any particular combination)
Meaning: according to dictionary, it conveys the idea of "with much effort". I don't know if せっかく can be used by its own, without forming any particular combination like the ones in the next groups. If so, I would really like to see an example.
・ せっかくの + Noun
Meaning: one-time thing (ex. "one-time opportunity") / rare, valuable thing I don't know if it can mean other things as well.
Meaning: since it is a rare ocassion, ...
・ せっかく ＋ 普通形 ＋ Noun
Meaning: something that has taken a lot of effort to make
Meaning: since you have done a lot of effort in doing something, I accept.
Meaning: I'm sorry that you have done a lot of effort in doing something, but I refuse.
Meaning: since something will be done or has been done, ...
Meaning: since you are going to do something, you could do also...
Meaning: just when something was done, ... (something negative)
Meaning: although you have done a lot of effort in doing something, ...
Meaning: it adds emphasis to something
The problem is:
- I don't know if all these combinations are correct (some of them are written by deduction).
- I don't know if all combinations are well-grouped.
- I don't know if in each group there are other possible combinations that I haven't listed or if there are missing groups.
- in some cases I don't know the exact meaning and in others I don't know if the meaning attributed to each group is correct or if there are missing meanings.
Therefore, I would greatly appreciate if you could help me.
Finally, if for each group you could please give me an example where I can see the meaning of せっかく that represents that group, it would help me a lot as well.
Thank you very much in advance for all of your help and sorry for the trouble.