You should, of course, adapt spelling lists and expectations to YOUR students and to individual needs whenever possible. For students who are not able to perform at such a high level, there are at least two ways to differentiate: Assign only a couple of words at  a time. OR, Assign much easier words. See my graded spelling word lists, and choose words from whichever lists seem best for each student. Remove all grade-level labels before assigning them to your 10th grader.