In creating a new neutral third person singular personal pronoun, a few things must be taken into consideration:
First, the new word should be completely novel.
It should not be found in the core English lexicon. There are already enough words in the English language with multiple meanings. The new word and its variations should not be in common usage currently.
Second, the new word should be neutral and not imply any gender.
Third, the new word should be unique.
Many English words have been derived from words taken from other languages. Words have been borrowed from all parts of the globe. The new word should be original rather than a copy of a neutral pronoun of another language.
With so many languages in use, it will be possible that any new word created could be found in some existing language dictionary. New words may have meanings in other language. However, the new neutral third person singular pronoun should be English and independent of other languages.
Fourth, the new word should be easy.
It should not change the sound or stress patterns of English. If it contained the same number of syllables as the masculine and feminine pronouns, it would be more acceptable than more complex words.
Creating the word
The letter "N" is selected to be the first letter of the neutral third person singular personal pronoun because it is in the middle of the alphabet and already begins the words neutral, neuter, and neither. All of the forms of the new neutral third person singular personal pronoun will begin with the letter "N".
One possible suggestion for the new pronoun and its variations would be to simply replace the "H" or "Sh" in he, she, his, her, hers, himself and herself with the "N". One could argue, "Why not use ne, nis, nim, nimself as the new pronouns? Or why not ne ners, ner, nerself?" It would be biased and unjust to use the endings from one gender and not the other for the neutral pronoun. To use all the male and female endings would be possible but complicated and unnecessary. To fabricate one set of pronouns that is a fair combination of the male and female third person singular personal pronouns is the logical answer to the dilemma.
The new neutral third person singular personal pronouns could be fair to both genders. They could be a combination of the current male and female third person singular pronouns.
Ne, nis, ner, nemself
Male Neutral Female
Explanations of derivations of case forms:
Neutral third person singular nominative or subjective case:
Ne is simple for the subjective singular pronoun. Delete the "h" from "he" and the "sh" from "she" and replace with "n" to make ne. That's fair to both genders.
Neutral third person singular possessive or genitive case:
The neutral third person singular nominative personal pronoun was easy to form because "he" and "she" have only one vowel after the initial consonant sounds of "h" and "sh". The possessive case adds a little challenge.
Start again with the "n" and add either of the gender endings to make "nis" or "ner". Which one would work best?
The feminine possessive noun modifier "her" has an "s" added to make it the independent possessive nominal "hers". Therefore, using the feminine ending ("er") for the possessive case would require the new word to change from "ner" to "ners" for the possessive and independent possessive respectively.
Because the masculine possessive and independent possessive are the same word, i.e. his, the masculine ending is used to make the new neutral third person singular genitive or possessive case personal pronoun "nis". No change is needed for the possessive and independent possessive; both are "nis".
Neutral third person singular objective or accusative personal pronoun:
Start with the letter "n". Because the masculine ending was used for the neutral third person singular possessive case, the feminine ending is used for the objective case making the new neutral third person singular objective personal pronoun "ner".
Neutral third person singular intensive or reflexive pronoun:
Start with the "n".
To be fair to both genders, add the "e" from herself, the "m" from himself, and then "self" to create "nemself".
The "i" from himself and the "r" from herself could be used, but that would create nirself which would be pronounced like "nerself" and sound like the feminine ending from herself. "Nemself" does not sound like himself or herself. Therefore, the new neutral third person singular intensive or reflexive personal pronoun is "nemself".