I'm going to blame myself.
I have read to my kids since before they were born so my kids have heard a lot of stories. Now my first grader is learning to read on his own and most any time he comes to a word he doesn't know he just makes something up. He knows how stories work in general, and how a particular story is unfolding as he reads it, so he just says something that would go along with what he's just read.
As a former reading teacher I know he's using context cues as opposed to visual cues in reading when he gets stuck. If he were using visual cues then he'd look at the first letter of the mystery word and try to sound out the parts he sees. But nope, he just picks a word that makes sense in the story regardless of how it matches with the word on the page.
There are lots of ways to help him pay closer attention to the words in a book. I'm working to teach him that he has to read what he sees. He can't just make stuff up.
This book by Mo Willems was a fun read last week because it helped direct his eyes to the words. The little chicks in That is Not a Good Idea
warn the characters over and over about impending doom. Each time they are more urgent and each time the reader has to make sure to read the right number of really-s. It's a simple but spot-on practice tool for a 1st grader and
it's an extra silly book. That's a win for me and a win for my new reader.
Let your librarian know if you're looking for books for your new reader. We love helping find just the right books for fun and practice!