One of Hocus Pocus' biggest questions is why only some people can hear Binx the cat talk throughout the movie, and the answer lies in the original script. The history and success of Hocus Pocus is one to be admired; it was originally envisioned as being a Disney Channel Original Movie - in many ways, it does feel like it comes from the same ilk as Halloweentown - but it was ultimately released in theaters - in the summer, no less. Given all that, it shouldn't have become such a hit.
Hocus Pocus did in fact bomb at the box office - no surprise since it came out in July and went up against Free Willy - but the Disney film found devotion on home video. It's now one of the Mouse House's most beloved Halloween movies ever released, right up there with The Nightmare Before Christmas. Every year, millions of people watch Hocus Pocus at home or in screenings around the country - but despite that, a sequel still hasn't happened yet. Hocus Pocus 2 could answer several questions left over by the first movie, but in the meantime, one of those questions is explained quite explicitly early in the script.
When Max, Dani, and Allison arrive at the Sanderson Sisters' house, Max jokes about lighting the cursed candle. That's when Binx the cat jumps out and attacks Max in an attempt to prevent him from bringing back the Sanderson Sisters. In that moment, Max throws Binx off of him and yells, "Stupid cat!" Right after that, the script version of Dani and Allison hear Binx tell them to tell Max not to light the candle. When Max asks why he can't hear the cat and only they can, Dani says because Max doesn't believe in magic. "Only those who believe in magic can hear him speak," she exclaims. It's such a simple explanation that falls in line with so many children's movies, but for some reason, it wasn't included in this film.
Rather than Dani explain to Max why she can hear Binx talk, the scene in the movie skips that dialogue and jumps to Dani and Allison telling Max they should leave. Of course, it's only moments later that Max can hear Binx speak, but it's only after he lights the black flame candle. Perhaps the explanation was cut to avoid a plot hole like this, but only moments after the candle is lit, all the lights go out, wind blows through the house, the floorboards jump and emit a green light, and three witches appear, who then perform all sorts of magic. All of that may have been enough to convince Max that magic is real - and so, he could finally hear Binx talk.
Even then, this wouldn't have resolved why Thackery Binx's parents couldn't hear him speak at the Sanderson Sisters' hanging. It seemed that the entire town believed in magic enough to hang the three witches, so they, logically, should've been able to hear their son's voice come from the cat - but they didn't. It's one of many questions that can be answered if Hocus Pocus 2 really does move forward... after all these years.