The usage of 'otherwise'

Question

Is the usage of 'otherwise' in this sentence correct?

I didn't study at all last night. Otherwise, I would have done better on today's test.

Answer 1

Normally, otherwise introduces a result when something with a "positive spin" is reversed:

Study hard ^{positive spin} for that exam; otherwise you won't do well.

It sounds a little odd when it introduces the result when something with a "negative spin" is reversed:

I didn't study hard for the exam. ^{negative spin}. Otherwise, I would have done well.

but it sounds OK when it is tacked on as a tail:

I didn't study hard for the exam. I would have done well, otherwise.

I don't think this is just my own idiosyncratic response, since other speakers I've asked feel the same.

Maybe that's because otherwise is frequently associated with urging to do something rather than to refrain from doing something:

Don't go out on that thin ice. Otherwise, you may fall through. ^{sounds odd}

Don't go out on that thin ice. You may fall through otherwise. ^{sounds OK}

P.S. What I think it is, after giving it a beer mug of thought, is that "wise" (manner) implies taking a course of action, not simply taking no action:

Take the parkway, otherwise you'll get stuck in traffic.

But if, on a semantic level, some other course of action is implicit, you can use otherwise with a negative spin:

Don't take the S-10, otherwise you'll get stuck in traffic.

It is not a binary take the S-10/don't take the S-10 scenario but "take the S-10/take some other route" scenario.