Here is a worksheet on the Latin roots dic and dict. They mean speech, to speak, and to proclaim (declare officially). This is a very productive root in English–think dictionary and dictation. If you take this worksheet, you’ll quickly perceive, I submit, that these are mostly words that high school graduates really ought to know.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.