A forcebound loses his ability to cast while in elemental form because he is limited to the languages and movement an elemental can make, but he can communicate normally with other elementals or elemental creatures of the same element as his new form. (Fire elementals speak Ignan, Water elementals speak Aquan, Earth elementals speak Terran, Air elementals speak Auran) 

A forcebound can use this ability an additional time per day at 6th level and 10th level and every two levels thereafter, for a total of seven times at 18th level. At 20th level, a forcebound can use wild shape at will. As a forcebound gains in levels, this ability allows the forcebound to take on the form of larger and smaller elementals. Each form expends one daily usage of this ability. 

At 6th level, a forcebound can use wild shape to change into a Medium or Tiny elemental. When taking the form of an elemental, a forcebound’s wild shape now functions as elemental body II. 

At 10th level, a forcebound can use wild shape to change into a Large or Diminutive elemental, a forcebound’s wild shape now functions as elemental body III.  

At 12th level, a forcebound can use wild shape to change into a Huge elemental and functions as a elemental body IV. 

At 14th level, a forcebound can use wild shape to change into a Greater elemental. 

The abilities you gain depend upon the type of elemental into which you change. You are also immune to bleed damage, critical hits, and sneak attacks while in elemental form and gain DR 5/—. 

Air elemental: As elemental body I except that you gain a +6 size bonus to your Strength, +8 size bonus to your Dexterity, and a +6 natural armor bonus. You also gain fly 120 feet (perfect). 

Earth elemental: As elemental body I except that you gain a +10 size bonus to your Strength, a -4 penalty on your Dexterity, a +6 size bonus to your Constitution, and a +8 natural armor bonus. 

Fire elemental: As elemental body I except that you gain a +8 size bonus to your Dexterity, a +6 size bonus to your Constitution, and a +6 natural armor bonus. 

Water elemental: As elemental body I except that you gain a +6 size bonus to your Strength, a -4 penalty on your Dexterity, a +10 size bonus to your Constitution, and a +8 natural armor bonus. You also gain swim 120 feet. 

At 16th level, a forcebound can use wild shape to change into an Elder Elemental. 

The abilities you gain depend upon the type of elemental into which you change. You are also immune to bleed damage, critical hits, and sneak attacks while in elemental form and gain DR 10/—. 

Air elemental: As elemental body I except that you gain a +8 size bonus to your Strength, +10 size bonus to your Dexterity, and a +8 natural armor bonus. You also gain fly 160 feet. 

Earth elemental: As elemental body I except that you gain a +12 size bonus to your Strength, a -6 penalty on your Dexterity, a +8 size bonus to your Constitution, and a +10 natural armor bonus. 

Fire elemental: As elemental body I except that you gain a +10 size bonus to your Dexterity, a +8 size bonus to your Constitution, and a +8 natural armor bonus. 

Water elemental: As elemental body I except that you gain a +8 size bonus to your Strength, a -6 penalty on your Dexterity, a +12 size bonus to your Constitution, and a +10 natural armor bonus. You also gain swim 160 feet.