When you commit an error you err. The expression is “to err is human.”
The new edition of Common Errors in English Usage is now shipping,
and it makes a great gift. When you order 5–9 copies and use the coupon
code FIFTEEN, you pay only $13.48 each. Order 10 or more for just
$12.15 each. All with free shipping in the US. Single-copy shoppers can
still use the coupon code and get the new edition for $15.