How do you say loving in Swahili?

Kupenda, infinitive (to love) or present particle (loving). It can be used as the subject of a sentence: kupenda ni kuishi: loving is living or to love is to live.

But to describe a person or act as loving you use the abstract noun for love, upendo: mtu mwenye upendo (a lovng person), Huyu ana upendo (this person is loving), kitendo cha upendo (a loving act).