Here are some ways to use the word "inattentive" in a sentence:
* "The student was inattentive in class and missed several key points."
* "Her inattentive driving led to a near accident."
* "He was so inattentive to his surroundings that he didn't even notice the fire alarm."
Essentially, "inattentive" implies a lack of focus and engagement. It can be a temporary state (like being tired or preoccupied), or it can be a more persistent trait.