Here is a context clues worksheet on the verb winnow. It’s used both intransitively and transitively. As I started writing this, I was surprised to learn the complicated set of definitions this word carries.
For this worksheet, I’ve limited the context to elicit the definition shown in the Merriam-Webster widget on my iPad, to wit “to sort or separate something.” This is the meaning of winnow in the vernacular, so I hope it serves students well.
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.