An expression used to show contentment for something

“Mmm, this is a tasty pie!”

An expression used to show thought or reflection

“Mmm, I see what you mean.”

An expression used to show being muffled or not able to speak clearly, as well as "mmph".

To make the um sound to express uncertainty or hesitancy.

Expression of hesitation, uncertainty or space filler in conversation. See uh.

“Let’s see... um... how about this?”