Can Black/Red Dragons talk in Pathfinder?

Question

In the Pathfinder Beginner's Box Gamemaster guide, it states that Reefclaws can understand language, but can't talk.

I can't find anything in particular in the Gamemaster Guide that explicitly states that Black/Red dragons can or can't talk.

Since it would help for characterisation for RP and massively impact a story; canonically, can dragons talk?

Answer 1

Yes, red and black dragons can talk.

Their monster stat block has the Language entry.

Languages Common, Draconic

This line, unless otherwise stated, indicates which languages the creature can speak. (see reference).

Languages: The languages most commonly spoken by the creature are listed here. For unusual creatures, you can swap out the languages known for other choices as needed. A creature with a higher-than-normal Intelligence score receives the appropriate number of bonus languages.

Reefclaws are a specified exception to this rule.

Languages Common (can't speak)

Answer 2

Dragons certainly can talk; Reefclaws is an exception stated to clarify.

Reasoning

1. The Dragon monster type has linguistics, bluff, diplomacy and intimidation listed as class skills, and certainly one or two of these could be justified as being used on their own without speaking but not all of them.

2. Dragons themselves are listed in the bestiary with multiple languages and, crucially at later ages the ability to cast spells as a sorcerer:

Spells: A dragon knows and casts arcane spells as a sorcerer of the level indicated in its specific description. Its caster level depends on its age, as shown for each type.

Casting spells as a sorcerer for the most part will require a verbal component, without this the dragon is going to be very restricted in it's spell selection (without using feats).

So at highest restrictiveness for dragons you could rule that before the dragon can cast spells it can't speak, but I think this is splitting hairs.

Creature Types

Note that in the creature types humanoids are listed as being able to speak, as are several other types; however known (presumed?) speaking creature types such as Brownies, Dryads and pixies are listed as type fae (Not Humanoid/fae) which isn't listed with the ability to speak. Certainly the Brownie at least as listed in it's flavour text as speaking, whilst the Dryad and Pixie are not.

When it comes down to it, as usual, what the GM wants. Speaking dragons are, after all, an exceedingly common fantasy trope.