Question Do these two sentences mean the same thing?- a) If I feel better tomorrow, I'll go out. b) Unless I feel better tomorrow, I won't go out.

Accepted:
December 19, 2016

Comments

I'd say that they have

I'd say that they have different meanings. I interpret (a) as implying that your feeling better tomorrow is a sufficient condition (all else equal, presumably) for your going out, whereas (b) implies that your feeling better tomorrow is a necessary but maybe not sufficient condition for your going out. That is, (b) seems more cautious, more hedged: (b) allows that you may not go out even if you do feel better tomorrow.

Compare: (c) If you feed your pet goldfish, it will flourish; (d) Unless you feed your pet goldfish, it won't flourish. Given how easy it is to overfeed a pet goldfish, (c) is doubtful: your pet goldfish may not flourish even if you feed it. Given that pet goldfish depend on being fed, (d) isn't at all doubtful.

Question Do these two sentences mean the same thing?- a) If I feel better tomorrow, I'll go out. b) Unless I feel better tomorrow, I won't go out. Accepted:December 19, 2016

Question Do these two sentences mean the same thing?- a) If I feel better tomorrow, I'll go out. b) Unless I feel better tomorrow, I won't go out.

Accepted:
December 19, 2016