Roll of Thunder, Hear My Cry uses relatively simple language to tell a very weighty story about racism, injustice and inequality in the Depression-era American South. Keep in mind that Cassie, our narrator, is only nine years old. So, while some of her language is a bit more complex than we might expect from someone her age, it should cause no major problems for students from about sixth grade on up.
Here are a couple of things to keep in mind as you read Cassie's story:
(1) Be on the lookout for $5.00 words like "imperious," (1.176), "clabber" (5.19), "nattily" (6.9) and "wan" (12.164), for example. So, you'll probably want to have a good go-to dictionary source nearby.
(2) Also, Mildred Taylor writes with lots of dialect, which re-creates Southern and African-American speech patterns. Expect to see dialogue like: 'I betcha Mama's gonna "clean" you, you keep it up' (1.3).
You might do a few double takes in the beginning, but stick with it. You'll develop an ear for it in no time (well, technically an eye, but it's all good) and things will smooth out.