Interjections are itsy bitsy words that show a wide array of emotions, anything from pleasure to hesitancy. They're fairly common in speech, so it's only natural they would pop up in print. 

But use sparingly.

Too many of these can inject an annoying buzz in the brain that lasts for days.

EXAMPLE:
   "I was right, eh?"
   "I don't know."
   "Eh? He said so, eh?"
   "I heard him."
   "No arguing with him, eh?"
   "Guess so."
   "He knows best, eh?"
   "Yep."
   "Eh? Eh?"
   "Here, take it."  

CLEANED UP:
    "I was right, eh?"
   "I don't know."
   "Eh? He said so."
   "I heard him."
   "No arguing with him."
   "Guess so."
   "He knows best."
   "Yep."
   "Eh?"
   "Here, take it."

EXAMPLE:
   "Your name Lee?" 
   "Uh, well ... yes sir."
   "You own that truck?"
   "Uh, well . . . yes sir, I got papers in the glove compartment."
   "Only one driving it today?"
   "Uh, well . . . I don't know how to answer that."
   "Simple yes or no will do."
   "Uh, well . . . all I can give you is a maybe." 

CLEANED UP:
   "Your name Lee?" 
   "Uh, well ... yes sir."
   "You own that truck?"
   "Yes sir, I got papers in the glove compartment."
   "Only one driving it today?"
   "I don't know how to answer that."
   "Simple yes or no will do."
   "Uh, well . . . all I can give you is a maybe."    
   

In my younger and more vulnerable years my father gave me some advice that I've been turning over in my mind ever since.

"Whenever you feel like criticizing anyone," he told me, "just remember that all the people in this world haven't had the advantages that you've had."

... Reserving judgments is a matter of infinite hope. I'm still a little afraid of missing something if I forget that, as my father snobbishly suggested and I snobbishly repeat, a sense of the fundamental decencies is parceled out unequally at birth.                                                                  

 - F. Scott Fitzgerald
    The Great Gatsby