Creating graded readers for new learners

I’m tying to create reading material for kids and adults who are learning to read for the first time and that is appropriate for their learning level.

I’m completely new to chatGPT, but with a little playing around, I’ve got closer to what I’m looking for. The question I have, is how to I force chatGPT to write a 50 or 100 word story using only the words off a given list?

What I’m getting is not a strict adherence to the list, but variations like running which is not on the list but run is. Also instead of saying “it is” its using the contraction It’s. I need chatGPT to only create things using only the list of words given. I know I’m missing something. Can anyone help me please?

Below is the prompt and word list I’m using.

write a 50 word story using only the words on the list without any plurals or tenses or contractions:

“I”, “a”, “the”, “go”, “in”, “is”, “me”, “to”, “can”, “it”, “you”, “see”, “get”, “are”, “then”, “give”, “him”, “here”, “ran”, “has”, “she”, “with”, “boy”, “who”, “we”, “and”, “like”, “did”, “run”, “for”, “was”, “on”, “at”, “as”, “if”, of, not, have, us, had, her, make, old, ride, tell, up, will, “why”, “am”, “after”, “all”, “be”, “big”, “can’t”, “car”, “do”, “day”, “fun”, “give”, “his”, “new” , “your”, “my”, “went”, “how”, “look”, “now”, “out”, “saw”, “that”, “want”, “this”, “play”, “but”, “animal”, “about”, “best”, “come”, “down”, “friend”, “from”, “were”, “good”, “house”, “little”, “no”, “when”, “said”, “what”, “jump”, “made”, “off”, “over”, “some”, “there”, “they”, “school”, “thing”, “where”.

The result I’m getting is…

I went to a big house to see a new car. The boy who ran it was here with me. He said I can ride in it if I give him some fun. I said “why not?” and we went for a play. But then, the car went off the road and we had to jump out. We were not hurt, but the car was old and broken. The boy said, “Now you see why I can’t have nice things.”

Ok, its not great, but I can edit to make it more understandable. But, despite being told not to use contractions, in the last line “can.t” has crept in again.

The prompt Ive written rapidly fails when I start to move up to the next reading grade. So really, I need to force it to only use the give word list but still use its own grammar rules.

Thank you so much for reading this very long question.