This is my language I will translate this in J'kopypdz meaning TheKing's.

Here is a sentence in english

Komo yz u zopjepso ip J'kopydz.

Tell me how you like it!

Ooooh, a new language. Sweet!

youk I veso poq vupdaudoz

Sorry

Yeah I love new languages

Yj poodz zero qemh.

There were some letters that I had to guess at, assuming a partial one-to-one or reversing relationship. It is more a cypher than a language. Though you did do an interesting job of making it at least reasonably pronounceable straight across (which is hard to do). What are the rules other than the transliteration? Such as changing the cypher when a letter is isolated or capitalized?

I did notice, though, that you used simply the letters of the English words. I prefer setting up a phonetic system, which makes it easier to do, and more realistic.

well ok.

When a word like J'kopydz the apostrophy is used as a vowel so it would be pronounced.

Ja-copy-daz

Could you give me examples?

I guessed that. Very good.

For example, a rule might be "When a 'i' is isolated it is left as 'I', but when in a word it is translated 'y'." That seems to be what you did, unless you did a typo.

No thats right! Any others?

I can't think of any more that you might have from the small samples I have been given. I still think you should do it phonetically (or make your own entirely), though. I am a language purist.

How do you do the phonic system?

Thanks

Remember that the book is written for readers, not for the world it's about. Think about how hard it is for casual readers to pronounce that. An example of a very pronounceable, reader-friendly language is Tolkiens' languages. Pronouncing Quenya and Gondor is very easy, and you don't have to know Elvish to read them.