Learn French: Il n'a entendu personne.

In the past tense (passé composé), most negative words like pas or rien (nothing) squeeze between the helper verb (a) and the main action (entendu). However, personne is a special exception! It always goes after the past participle.

Why isn't there a pas in this sentence?

The word personne replaces pas. In French, you cannot use both together to make a standard negative sentence. Saying Il n'a pas entendu personne would be incorrect, so you only pair ne (shortened to n' here) with personne.

The translation says "anyone", but doesn't personne mean "nobody"?

Yes, ne ... personne literally translates to "nobody". A word-for-word translation would be "He heard nobody." However, in natural English, we usually say "He didn't hear anyone" to avoid a clunky double negative, which is why the English translation looks slightly different!

Why is it n'a instead of ne a?

Whenever ne is followed by a word starting with a vowel (like the helper verb a), the e is dropped and replaced with an apostrophe. This is called elision, and it makes the sentence flow more smoothly when spoken.