Can't write sentences that end with a specific letter.

ChatGPT can't do anything related to words itself. For example, it can't count words, syllables, lines, sentences. It can't encrypt and decrypt messages properly. It can't draw ASCIII art. It can't make alliterations. It can't find words restricted in a sense, like second syllable, last letter etc.

To help improve such prompts:

Add “exactly [number] letters”
For example - “exactly three letters”

Not good for riddles:

Riddle:

An evil warden holds you prisoner, but offers you a chance to escape. There are 3 doors A, B, and C.

Two of the doors lead to freedom and the third door leads to lifetime imprisonment, but you do not know which door is what type.

You are allowed to point to a door and ask a single yes-no question to the warden. If you point to a door that leads to freedom, the warden answers your question truthfully. But if you point to the door that leads to imprisonment, the warden answers your question randomly, either saying "yes" or "no" by chance.

What single question can you ask which will guarantee your escape for sure?

ChatGPT (gives 50/50 answer):

"You can ask the following question: "Is the door I am pointing to the one that leads to lifetime imprisonment?"

If you are pointing to the door that leads to lifetime imprisonment, the warden will randomly answer "yes" or "no," and you will have a 50% chance of guessing correctly and escaping.

If you are pointing to one of the doors that leads to freedom, the warden will truthfully answer "no," and you will know for sure that you should escape through that door."

Other limits:

It also can think a period is a word or a letter in this specific case for example. So you specifically have to to ask it not to count that as a letter.