subjunctive mood - Must conditional sentences begin with "if?"

I've been looking at conditional sentences (conditional clauses).

Every example I've see is along the lines of, "if [x] then [y]."

I've seen alternatives/substitutes for the if part:

• were I you (instead of "if I were you")


• on condition that


• unless


• were

Yet, these still follow the same pattern: "condition [x] then [y]."

Is that the only way to have a conditional?
Is it not possible to invert/switch around the structure?
Would it still be a conditional clause (or conditional sentence) if I put the condition after the occurance?

• If he eats that, he'll be sick.


• He'll be sick if he eats that.


• Unless you win this round, you are out.


• You are out unless you win this round.

If those are not conditionals, what are they?
Would they be considered as "acceptable" if I were to be editing/rewriting something, or would it be seen as bad/improper/incorrect/having a sufficiently different implication?