"let alone"

[cephalopod9]

Grammar question that's been buggin' the crap out of me, don't know how to search for it:
When using a phrase with the following format "it's too X for Y, let alone Z" is it Y or Z that is the more severe?

Examples: "it's too hot to go for a walk, let alone run a marathon"
or
"It's to heavy to carry home, let alone pick up off the ground"

[Lazar]

Grammar question that's been buggin' the crap out of me, don't know how to search for it:
When using a phrase with the following format "it's too X for Y, let alone Z" is it Y or Z that is the more severe?

Z is more severe. What it means is roughly, "We can't even do [Y, the less difficult thing], so we definitely can't do [Z, the more difficult thing]."

Examples: "it's too hot to go for a walk, let alone run a marathon"

Right.

"It's to heavy to carry home, let alone pick up off the ground"

Not right.

[SlyReaper]

Z is the more severe one. That is, your first example is the one which makes sense.

[existential_elevator]

I would argue that the second one also makes sense:

"It's too heavy to carry home, let alone pick up off the ground"

"I can't carry this home, setting aside the matter of picking it up"

From what I understand, "let alone" should have a similar usage to "not to mention".

[Lazar]

I would argue that the second one also makes sense:

"It's too heavy to carry home, let alone pick up off the ground"

"I can't carry this home, setting aside the matter of picking it up"

From what I understand, "let alone" should have a similar usage to "not to mention".

No, that doesn't sound natural to me. Even the substituted version "I can't carry this home, not to mention picking it up" strikes me as an incoherent thing to say - if I were trying to express something like, "I may be able to pick it up, but I can't carry it home," that's definitely not how I would express it.

Or to put it another way, while I agree that "let alone" is roughly equivalent to "not to mention", I don't think either of them means the same thing as "setting aside". "Not to mention" is an idiomatic phrase which doesn't have the literal meaning of "we're not mentioning this".

[Felstaff]

I can't even do a simple task, let alone a significantly harder task.

[Iulus Cofield]

I think both examples are cromulent in that the second idea is the more difficult one.

[Lazar]

I think both examples are cromulent in that the second idea is the more difficult one.

No, carrying the thing home is more difficult than merely picking it up. That's why OP used it for the second example.

[cephalopod9]

I'm kind of glad just to be seeing some disagreement, as I wasn't 100% sure I didn't just hear someone misuse it once and my brain made that into a trend.

[Qaanol]

I think both examples are cromulent in that the second idea is the more difficult one.

No, carrying the thing home is more difficult than merely picking it up. That's why OP used it for the second example.

Technically, picking something up requires work (against gravity) whereas carrying something at a constant height does not necessarily entail any physical work.

[cephalopod9]

That assumes you are able to glide along, holding your item at a perfectly constant height, and some how manage to get it to carryable height without lifting it. That's not how "carrying" tends to work for humans.

[mojacardave]

That assumes you are able to glide along, holding your item at a perfectly constant height, and some how manage to get it to carryable height without lifting it. That's not how "carrying" tends to work for humans.

This is XKCD. We do not concern ourselves with the physics of the real world. XKCD space is a frictionless vacuum.

[Alcas]

The first one is definitely correct and the second one not.
To express the idea of the second one, I would say "It's too heavy to carry home, or even pick up off the ground."