Another useful druid spell is Beastspeak (10 minutes per level).
http://www.d20pfsrd.com/magic/all-spells/b/beastspeak
When you're in the form of an animal (such as when you are using wild shape or are affected by a polymorph effect), you can speak normally, including when you cast spells with verbal components, and you sound like your normal self when you speak. You can cast this spell while in animal form, using animal-appropriate somatic components.
However I do not believe you can make a creature speak who has never spoken before.
For that you would need the fifth level druid spell Awaken, which should also work on magical beasts.
http://www.d20pfsrd.com/magic/all-spells/a/awaken
You awaken a tree or animal to human-like sentience. To succeed, you must make a Will save (DC 10 + the animal's current HD, or the HD the tree will have once awakened). The awakened animal or tree is friendly toward you. You have no special empathy or connection with a creature you awaken, although it serves you in specific tasks or endeavors if you communicate your desires to it. If you cast awaken again, any previously awakened creatures remain friendly to you, but they no longer undertake tasks for you unless it is in their best interests.
An awakened tree has characteristics as if it were an animated object, except that it gains the plant type and its Intelligence, Wisdom, and Charisma scores are each 3d6. An awakened plant gains the ability to move its limbs, roots, vines, creepers, and so forth, and it has senses similar to a human's.
An awakened animal gets 3d6 Intelligence, +1d3 Charisma, and +2 HD. Its type becomes magical beast (augmented animal). An awakened animal can't serve as an animal companion, familiar, or special mount.
An awakened tree or animal can speak one language that you know, plus one additional language that you know per point of Intelligence bonus (if any). This spell does not function on an animal or plant with an Intelligence greater than 2.
Magical beasts are
similar to animals but can have Intelligence scores higher than 2 (in which case the magical beast knows at least one language, but can't necessarily speak). Magical beasts usually have supernatural or extraordinary abilities, but are sometimes merely bizarre in appearance or habits.
http://www.d20pfsrd.com/bestiary/monster-listings/magical-beasts