After a construction accident, Jared was left without the ability to comprehend and express language due to damage sustained in his:

left temporal lobe.

Explanation:

The temporal lobes of our brain perform numerous functions such as memory, facial recognition, recall and sound processing, etc. Damage to our temporal lobes may result in a number of impairments in our bodies. The left temporal lobe is a very important part of our brain that deals in understanding and using language. Damage in left frontal lobe may result in the inability to comprehend and express language. Damage to our left temporal lobe may also result in abnormal changes in our emotions like euphoria, deja vu, fear, etc.