If you’re a stickler for usage, or want to give your students a chance to become sticklers in their own right, then this English usage worksheet on the past participle shrunk and the simple past tense verb shrank might be one avenue to bring that endeavor to fruition. For the record, shrunk is the past participle, so it must be used with the helping verbs had and have. Shrank, on the other hand, is the simple past tense of the verb shrink.
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.