It turned up in a discursive lesson I taught in a personal development class yesterday (on, of all things, what’s “wrong” with Eric Cartman of “South Park”), so here is a context clues worksheet on the verb assert. It is used only transitively, apparently, which makes sense if one thinks about where and how to use it in speech and prose.
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.