Subjunctive in purpose clauses (so that)

[Jesusengland]

Hello.

Could you tell me the differences in meaning in these purpose clauses?

- Why don't you take a day off so that you recover properly / can/may/will/shall recover properly?
- We worked hard so that we save a lot / would/might/could/should save a lot.

Thank you very much.

[Jamie (K)]

I think you're making something complicated out of something that's not. Any difference in meaning depends on the differences in meaning among the modals you are using. Maybe you can take the sentences one by one using each modal and tell us what you think the difference is. We can tell you if you're correct.

(Somehow I have a feeling someone is asking us to do his homework here.)