Let alone is used after a statement, usually a negative one, to indicate that the statement is even more true of the person, thing, or situation that you are going to mention next.
[emphasis]
It is incredible that the 12-year-old managed to even reach the pedals, let alonedrive the car.
See full dictionary entry for let
let alone in British English
much less; not to mention
they can't afford a meal out, let alone a holiday
See full dictionary entry for alone
let alone in British English
a. (conjunction)
much less; not to mention
I can't afford wine, let alone champagne
b. let be
to refrain from annoying or interfering with
let the poor cat alone
See full dictionary entry for let
let alone in American English
1.
to refrain from bothering or interfering with
: also leave alone
2.
not to speak of
we hadn't a dime, let alone a dollar
See full dictionary entry for alone
let alone in American English
see let1 (sense 1)above & see the phrase under alone
See full dictionary entry for let
Examples of 'let alone' in a sentence
let alone
They would barely hold open a window, let alone a door.
Times, Sunday Times (2016)
He could launch a new era, let alone a few attacks.
Times, Sunday Times (2016)
But how do tell that to anyone, let alone your own father?
Times, Sunday Times (2016)
Let alone write like that.
Times, Sunday Times (2016)
Most could not read or write, let alone speak English.
Times, Sunday Times (2016)
Let's not think about it, let alone plan.
Times, Sunday Times (2016)
Those who have examined innovation closely know that it is a myth that it comes from brilliant thinkers, let alone ones who live in ivory towers.
Times, Sunday Times (2017)
There is no effective opposition in Britain in the conventional sense, let alone an alternative government waiting in the wings.
Times, Sunday Times (2016)
The report says Britain could one day be unable to defend its own shores, let alone carry out the many security tasks it currently undertakes worldwide.
The Sun (2016)
Let alone still dress like they did?
Times, Sunday Times (2016)
They are not best placed to choose their careers, let alone leave school.
Times, Sunday Times (2011)
It is not a thing, let alone a person.
Christianity Today (2000)
There was some doubt whether he could see the board, let alone the segments.
Times, Sunday Times (2015)
No adult appeared to look after them - let alone feed them.
Times, Sunday Times (2009)
Something that was so likely to happen cannot be called a catastrophe, let alone a surprise.
Times, Sunday Times (2006)
It is unthinkable that anyone should take such photographs, let alone publish them.
Times, Sunday Times (2012)
As people get more they do not become satisfied with a little more, let alone with less.
Peter F. Drucker MANAGEMENT: task, responsibilities, practices (1974)
That would have been a tough baptism for anybody, let alone somebody with great expectations on his shoulders.
Times, Sunday Times (2013)
What amazes me is that anyone could have the audacity to swear this sort of thing, let alone lawmakers.
Times, Sunday Times (2010)
Government will not become less pervasive, less powerful, let alone less expensive.
Peter F. Drucker THE ESSENTIAL DRUCKER (2001)
This can leave doctors, let alone patients, in the dark about their real medical value.
Times, Sunday Times (2008)
The energy it takes to get out of bed, let alone leave the house, is overwhelming.
Times, Sunday Times (2013)
Do not transfer money to the seller's account for a car you have not seen, let alone driven.
Times, Sunday Times (2015)
My mum was so consumed by her own circumstances that she couldn't look after herself, let alone me.
Times, Sunday Times (2007)
No one can predict what the weather will do next week, let alone what it will be like in 50 years time.
The Sun (2013)
Over the next two matches, let alone next summer, they are going to have to find the capacity to produce something more.
Times, Sunday Times (2013)
What he did not know was that I can barely drive, let alone with style.
Times, Sunday Times (2008)
Most students don't know what they want to do next week, let alone how they want to spend the rest of their lives.