"It'll make you sick, if not kill you."

“It’ll make you sick, if not kill you,” and expressions with the “if not”, I’d always thought I’d understood. I’d taken it literally - in this example, “You’ll at least get very sick from that. If it doesn’t make you sick, it’ll kill you.”

But the way I’ve heard the “…if not…” used lately, the example seems to mean:
“I admit that it won’t kill you. But it will make you feel just lousy.”

So, what does the “…if not…” mean?

Exactly what you thought. The fact that some people misunderstand it doesn’t change anything.

I agree. I’ve never encountered the second “meaning,” but it sounds like some people don’t know their ifs from their buts.

Similarly, I’ve always used the phrase “let alone” to differentiate between the greater and lesser, with the greater **following ** “let alone”. For instance, *“I can’t color in the lines, **let alone ** draw.” * But lately I’ve heard it used a lot in the opposite way.

I’m pretty sure that’s wrong, on a level with “I could care less”, but I’m no authority. Have I been misusing that phrase all these years?

There’s a fairly high level of misuse of “If” going on these days. It’s not a synonym for “although”, “in case”, or “even if”.

I’m often informed that (e.g.,) “Joe brought bagels for everyone, they’re in the kitchen if anyone wants them”. (I don’t know for sure where they are if no one does, but I have a sneaking suspicion they remain in the kitchen under that circumstance as well).

I have a relative who, when something unexpected or unusual happens, claims “I don’t reckon I’ll ever see anything to beat that if I live to be a million”. (Given its rarity, I’d think it even less likely you’d see that if, as would seem probably, you don’t)

I remember having to get used to “but if” in Chaucer. It means “unless.” It’s fun to use sometimes, if you like confusing people.

The correct sense is “If it doesn’t kill you, it will at least make you sick.” So the second sentence isn’t quite right here. It would be better to replace it with “It might even kill you.”

Oh, this one drives me nuts too, DianaG. If you’ve been misusing it, then so have I. And given that it doesn’t make any sense with the less following the greater, I’m going to keep using it our way!

Huh. I interpret the expression: “He is evil, if not the antichrist” to mean: He is evil, but probably not the antichrist.

The key disqualifier is the term “not.” I don’t see how “not” takes on the meaning of “he is.” Modern idiom/vernacular may have twisted this expression to create “he is evil AND probably the antichrist too,” but I don’t see it.

That people use this phrase incorrectly doesn’t make it grammatically correct.

Example two: “She is pretty, if not beautiful.” Interpretation: She is pretty, but perhaps not beautiful.

Example three: “He is bright, if not a genius.” He is bright, but probably not a genius.

Example four: “He is manipulative, if not downright evil.” Yes, manipulative, not evil.

Make sense? Not to millions, including those in the media.

Try it this way:

“Even if he’s not the antichrist, he’s still evil.”

or to be even more obvious about it

“He may be the antichrist, but if he’s not—even if he’s not that evil—he is evil.”