###Etymology [Wiktionary][1] tell us that : >(*Nom*) Du latin *passus* (« pas, enjambée, marche » ou « trace de pas »). >(*Adverbe*) De l’usage en ancien français d’ajouter un substantif signifiant « le moindre » après *ne* : >>Je ne bois goutte. — Je ne mange mie. — Je ne marche pas. A *"pas"* is a step, the shortest measure of distance. In old french, to negate, we were using *"ne"* with the shortest measure of what we were doing. > Je ne bois goutte → I do not drink, even a single drop. > Je ne mange mie. → I do not eat, even a little piece of bread (*"mie"* is the *inside of the bread*, but underline the special meaning here) >Je ne marche pas. → I do not walk, even a single step. > L’usage de *pas* s’est généralisé par un cycle de Jespersen et la négation *ne* est pour sa part devenue optionnelle dans le langage courant : >>Je marche pas dans cette combine. — J’vois pas où tu veux en venir. <sub>I do not walk in this ploy (I don't accept). — I do not see where you want to go (what you mean).</sub> So, **in conclusion**, we can use *"pas"* for nearly every negation and ***"ne"* became optional progressively**. ---------- ###General case To come back to what you are asking : > However, I wonder if *"ne"* can also be omitted in other structures, notably with *"personne"*. Yes, you can in all cases when you are **talking**. When you are writing or in more formal context, it is necessary to write/say the full negation. As @Chop says : > When spoken, it is also usual to shorten it, just pronouncing the **N** (a sort of a contraction). When speaking formally, *"Je n'suis pas d'accord."* will be better than *"Je suis pas d'accord."* ---------- ###You example : >For example, *"Personne ne me connaît ici"* means that *"No one knows me here"*, but can I speak *"Personne me connaît ici"* to express the same thing? *"Personne me connait ici"* will be understood as *"Nobody knows me here"* [1]: http://fr.wiktionary.org/wiki/pas