Plus, Giggleton, and Catlady..
I was finding errors in paperback books all through high school and college. These are errors that in some cases the author made, and in some cases got inserted when the publisher was revising the novel. (Yes, it may surprise you to know this, but once you sign the contract, they often CAN revise and change your novel.)
Those errors, if grammatical, or spelling.. should we change them, or not? Are they the author's? Or are they the publisher's? Did the author intend for that sentence to be there? Or not?
You'll never likely know, as most contracts bar authors from ever releasing pre-production work. But the error may or may not be corrected in the next printing, in which case, you probably wouldn't know anyway
