Words with "cap-" as a prefix:
* Capital: Relating to the head or a city that is the center of government.
* Captivate: To attract and hold the attention of someone.
* Capsule: A small, enclosed container, especially for medicine.
* Capricious: Subject to sudden changes of mood or behavior.
* Capacity: The maximum amount that something can hold or produce.
* Capriole: A leaping movement by a horse, in which the hind legs are raised and brought forward.
* Captain: The leader of a team or group.
* Captivate: To attract and hold the attention of someone.
* Captive: A person or animal that is held prisoner.
* Capsize: To overturn or turn over.
Note: "Cap-" is not a very common prefix.
Let me know if you'd like to see examples of words with other prefixes!