"Five handsome men"
Translation:ʻElima kāne uʻi
Alice Namekelua wrote a beautiful song called "Nani." It is about young girls learning hula. This is what is cited on the Huapala website: "One day, in 1949, the composer was teaching hula to a group of young girls at the playground. They were all so pretty and she imagined how beautiful they would be when they grew up. This song was composed for them." Huapala is a superb website that provides the lyrics of hundreds of Hawaiian songs along with translations and sometimes brief commentary. This seems like evidence that nani can apply to people.
I think the difference between nani and u'i is sort of nuanced from the feeling you get. Nani is "beautiful" and so can apply to both people (generally feminine) and things.
U'i is also "beautiful" but beauty by virtue of its youth. So there are other connotations with that.
Leilani (wahine 'opio) might be referred to as both nani and u'i, but Tūtū is usually just nani.
If you call grandma u'i, she might be suspicious that either you have poor eyesight or need something from her.
But I am not fluent. I would love a fluent speaker to better define it.