It's difficult to give examples for the WAIS ethically...but I can say generally that the easier vocabulary items tend to be more concrete, while the harder items are more abstract.
This is why, if you want to improve your vocabulary, it is important to read complex texts that include abstract, nuanced ideas, across a wide range of topics, experiences, and styles, which, of course, will have the more critical long-term benefit of expanding your experience and understanding of the world, other people's perspectives, and life in general!
