You can check your special attacks by tapping the "I" button at the top right corner during a fight. There are four different special attacks.

Attack Buff: Three elements of the same type; increases attack.
Defense Buff: Two elements of one type, one different; increases defense.
Dexterity Buff: Element 1, element 2, element 2; Increases DEX stat.
Recovery Buff: Element 1, element 2, element 1; increases the REC stat.