This 33 page booklet contains exercises and charts in a variety of formats which clarify the usage of that pesky apostrophe. It has been used successfully from the early elementary grades to adult.
Possessions, Plurals, & Apostrophes is great for use in a workshop model as a mini-lesson, or evaluation for lesson planning.
Save yourself valuable time searching for other resources! Please check out all my other resources. They are easy to follow and students will thank you for de-mystifying so many objectives!