growf
No, unhappy, negative
growlf
Very negative, unhappiest
murph (slang)
Contentment
[citation needed]
yaff
A neutral (slightly positive) sound
yarf
A neutral (slightly negative) sound
yerf
Happy, positive, a greeting
yiff
Originally: Happiest, very positive, yes, an exuberant greeting; Now: sex
yip
Happier, more positive
yipp (slang)
Sexual proposition
[citation needed]