Most students don't know what they want to do next week, _________ the rest of their lives.

• কোনো কিছু ভাবা  যায় না বা চিন্তা করার প্রশ্নই উঠে না বোঝাতে let alone ব্যবহার হয়।
• সাধারণত negative sentence এর পরে  let alone ব্যবহার হয়।
যেমন:
Most students don't know what they want to do next week, let alone how they want to spend the rest of their lives. 
He does not even trust his children, let alone his neighbours.
Some people never even read a newspaper, let alone a book.