Theory:

Then one day he found his cat playing with a little doll and he grabbed it away. To his surprise, it wasn’t a doll at all, but a man of the tiniest size. He had a little wool shirt with old fashioned britches and a tall hat much like a witch’s. He yelled, “Save me! Don’t give me back to that cat. I’ll grant you a wish, I promise you that.”
Explanation:

One day he saw his cat playing with a small doll and was amazed to find that it wasn’t a doll, it was a man of the smallest size. It was wearing a woollen shirt, old-fashioned trousers and a tall hat which looked like a witch's hat. The doll exclaimed and asked Patrick to save him and not to put him back to the cat. In return, the doll promised Patrick to carry out one of his wish.
 
Meanings of difficult words:
 
Number
Word
Meaning
1.
Britches
Breeches, or short trousers
2.
Grabbed
Caught
3.
Tiniest
Smallest
Reference:
National Council of Educational Research and Training (2006). Honeysuckle. Who did Patrick's Homework - Carol Moore (pp. 7-10). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.