What is the author's style in Abel's Island by William Steig?

The language of this book tends to be informal. The sentences are constructed in a manner that is common to everyday people, yet the book is about a mouse and is set in 1907. The sentences follow the complex rules of grammar. Slang is not used. Abel, the main character, does not have much dialogue because he is alone most of the time. When he thinks, he uses everyday language to express his thoughts and emotions. There are difficult vocabulary words interspersed throughout the text. The language adds a depth to the book that allows the reader a glimpse into the dangers and survival methods of living on the island for an entire year.