This activity helps students to grasp the concept of word parts by asking them to create their own words from Latin roots and Greek stems. I used this as a group activity, but it could also be done individually. Each student or group gets a recording page (pages 1-2 of the download).
Next, students are given a number of the root and stem cards (depends on how many groups, etc.). Students are to put two word parts together to form a new, often made-up, word. For instance, a group might have the card "super" (meaning "over") and "dict" (meaning "say"). They might combine these into the word "superdict" and say that it means "to say too much."
Once students are given the chance to create a few words, cards are rotated and the process starts again with a new set of cards. You could also print an entire set of the cards for each group, rather than splitting them up and rotating them.
This activity is great to get students to understand that each word part has its own meaning, and that each of those meanings contributes to the meaning of the word as a whole.