Meanings
How to pronounce "let alone":
AU
Much less; to say nothing of; used after one negative clause to introduce another, usually broader and more important clause, whose negation is implied by the negation of the first. However either of these instances mentioned can be applied with the use of let alone.
Example: "He couldn't boil water, let alone prepare a dinner for eight."
not to mention, as well as; used after one item, to introduce a further item which is entailed by the first.
Example: "The restaurant didn't waive uniform protocol for any waiter, let alone him."
To leave alone, let be; to stop bothering.
Example: "I wish he would let me alone so I could get some sleep."
Example Sentences
1
I can't afford to buy a new car, let alone a luxury car.
2
She couldn't even cook scrambled eggs, let alone a four-course meal.
3
He can't run for five minutes without getting tired, let alone complete a marathon.
4
I didn't have time to wash my hair this morning, let alone style it.
5
They didn't invite me to the party, let alone ask me to be the host.
