The verb leave means "go away from" or "put in a place." Let means "permit" or "allow."
- "I never let schooling interfere with my education." (Mark Twain)
- Leave me alone.
- "On the less sophisticated levels of American speech, leave is a popular substitute for let. On educated levels, the following distinction is carefully observed: let means allow; leave means depart. (There are a few idiomatic exceptions to this rule, but they present no problem.) 'Let me go' is preferable to 'Leave me go' even on the most informal of occasions, and a sentence like 'Leave us not mention it' is not considered standard English."
(Norman Lewis, Word Power Made Easy. Simon & Schuster, 1979)
- "Traditionally, there has been a distinction: leave me alone means 'leave me by myself (in solitude)'; let me alone means 'stop bothering me.' But only extreme purists will fault someone who uses leave alone in the nonliteral sense. Today that phrase is far more common than let alone."
(Bryan A. Garner, Garner's Modern American Usage. Oxford Univ. Press, 2009)
(a) Don't ______ the children unattended.
(b) Don't ______ the children play near the grill.