Emphasizing contrast between two statements of differing probability

To highlight the improbability of a second statement relative to the first

Comparing two unlikely events, describing impossibility relative to another impossibility

Formal and informal English, including spoken and written discourse

let alone

let alone

A more extreme clause or phrase indicating something even less likely or possible than the preceding statement

• I can't even
• let alone
• you won't pass without studying
• let alone graduate with honors

• not to mention
• much less

Using let alone to imply similarity or equal likelihood between two events

not to mention, much less

Learners may incorrectly place let alone after a positive statement or use it to imply greater likelihood

• Contrasting connectors

Emphasizes significant difference in probability between two statements

Creates rhetorical force by highlighting the improbability of an event

I'm struggling to make ends meet, let alone plan a vacation

This chunk is a scalar additive connector that emphasizes a significant gap in possibility between two statements. It is used to highlight that the second statement is far less probable or possible than the first, often in contexts where the first statement is already negative or limiting.

not to mention