The antonyms for "become inattentive" include "pay attention," "focus," "be alert," "stay vigilant," and "concentrate." These words represent the opposite of being inattentive or disengaged. When someone is paying attention, they are actively absorbing information, processing it, and responding appropriately. Being alert means being aware of one's surroundings and being able to respond quickly to any changes. Staying vigilant involves staying alert and focused over an extended period. Concentrating is a deliberate and focused effort to process information accurately. These antonyms represent essential traits to cultivate in people who want to be productive, efficient, and successful in their endeavors.