The innervation of the tongue is basic anatomy, but can be easily confused due to its complexity. The three basic components of the innervation are motor, sensory, and taste.
The motor component to the entire tongue is supplied by the Hypoglossal nerve (CN XII), except the palatoglossus muscle, which is supplied by the pharyngeal branch of the Vagus nerve (CN X).
The sensory and taste components are divided up into two parts: the posterior 1/3 of the tongue and the anterior 2/3 of the tongue. Both the sensory and taste components of the posterior 1/3 are supplied by the Glossopharyngeal nerve (CN IX). The sensory component of the anterior 2/3 is supplied by the lingual branch of the mandibular branch (V3), which comes off of the Trigeminal nerve (CN V). The taste component of the anterior 2/3 is supplied by the chorda tympani branch of the Facial nerve (CN VII), which is carried by the lingual branch.
Below is a figure summarizing the above information: