also uh-huh
Frequency: The word is one of the 3000 most common words in English.
Uh huh is used in writing to represent a sound that people make when they are agreeing with you, when they want to show that they understand what you are saying, or when they are answering ‘yes’ to a question. (INFORMAL)
‘Did she?’—‘Uh huh.’
CONVENTION