"ʻO kēlā keiki kāne kaʻu pōkiʻi."

Translation: That boy is my youngest.

[BethKing-M]

If youngest "child" or "sibling" isn't indicated, how do you know which guess to make?

[Eliza727459]

If it's sibling, then it would be O-class, and you would use "ko'u."

[BethKing-M]

So, I guess you just leave it out and hope to figure it out in person??

[KarinLynn1]

I think what Eliza is saying is that if it's a relationship (relative), you can tell by the 'a' or 'o.' I would guess that this sentence could be referring to a friend, too (isn't that 'a' class?) - just as in English, the sentence leaves you with not all of the information.
CORRECTION: Reading further in comments, I see that the dictionary def is 'The youngest member of a family' so that means it can't be hoa. (Decided to leave my comment in in case someone else jumps to the same conclusion I did.)

[Mak511906]

The translation given here was my first choice until in my search for the noun described by the adjective "youngest" and couldn't find one. So I moved the noun "boy" to the end of the sentence to make sense in English, as that is occasionally seen on DL. I would love to see some explanation given for some of the more confusing lessons

[Mak511906]

Second time getting this sentence to translate - and still leaving me wondering "my youngest what?"

[RonRGB]

https://manomano.io/definition/32777

pōkiʻi

[LA] 1 n The youngest member of a family; ka hanau muli loa; the youngest born of several children. The younger of two children of the same sex; an endearing appellation.

(duolingo) pōkiʻi = youngest sibling of the same sex, youngest child, youngest.

[Jessi784299]

youngest can also be a noun in English, like "He is the youngest." :)

[kelii....]

... child

[MacKinzieRob]

Nope Jessi is right. A lot of folks say "He's my youngest"

[deactivated user]

And "muli loa" means what?

[deactivated user]

This favorite child is the youngest. "'O kēia keiki punahele ka muli loa."

[Kiha183527]

could be child or sibling by your definition

[Eliza727459]

But by sentence written with A-class "ka'u" you know their is a generation difference with the speaker being the older (parent) generation.

[Eliza727459]

There... oops.