Um-hum

Mr. PEPINSTER: (Foreign language spoken) LYDEN: Um-hum, okay.

Secret Stations And Boyhood Love On The Paris Metro 2010

"Um-hum," I said, trying to sound neutral but encouraging.

All Together Dead Harris, Charlaine 2007

"Um-hum, said Ah was a good shot an 'all that, so they'd let me off this time."

Three Soldiers John Dos Passos 1933