Diminutives
Diminutives (e.g. -(t)je in Dutch, -aki in Greek, xiǎo- in Mandarin Chinese) are morphemes that mean 'small'
They are often used to express intimacy
- Intimacy towards the referent, e.g. 'Look at this doll-DIM!'
- Intimacy towards the hearer, e.g. 'Let's read a book-DIM'
Cf. Klingon morphology
You could consider morphology encoding other types of added emotional meaning (e.g. anger, admiration, hatred, disgust) for your language