I have used a few free verbs study packs I've found on TPT to introduce the concept.
I love this one by because she shows the anchor chart she made and the three different types of verbs, which can be confusing for the little ones.
Free Verb Activities by Amy Lemons
This one had a fun action verb detective activity the kids loved.
Verb Activities by Rachel Lamb
Finally, after playing scattergories with a group of friends one weekend I decided to adapt the game for verbs. We had such a great time playing this game!
I wrote up some directions and a recording sheet in case you want to add this game into your plans when you study verbs.
Click the picture to view this file in google docs.