Question

make a word that means \feeling very happy.\ (image shows word tiles: thought, less, joy, ful, use in two boxes, with joy and ful highlighted in yellow)

Explanation:

To form a word meaning "feeling very happy", we combine the root "joy" (related to happiness) with the suffix "ful" (meaning full of). "Thoughtless" means without thought, "useful" means having use, so "joyful" is the correct combination as it means full of joy (very happy).

Answer:

joyful