Listed below are 46 words taken from a popular book (popular as in "award-winning best seller"):
a am anywhere are be boat box car could dark do eat fox goat good here house I if in let like may me mouse not on or rain Sam say see so thank that the them there they train tree try will with would you
The original list had 50 words; I've left out four of them - because they form the title of the book.
Name that book. Answer in the comments section.