"Is Kawika tall?"
Translation:Lōʻihi ʻo Kawika?
"He" is actually an indefinite article, almost exactly like "a" or "an" in English. When it is at the start of a sentence, it indicates that the sentence will be equating two things, so it sort of acts like the verb "to be". There are other things that can indiacte such an equational sentence, like "'O". You use "he" when one of the two things you are equating is an indefinite (i.e. the English has "a" or "an"): "Kawika is a tall man." = "He kāne lō'ihi 'o kawika." If there is no indefinite article in the English, then you're going to want to start with the "'o" term instead.: "Kawika is the teacher." = "'O Kawika ke kumu."
In English we equate not only noun phrases, but also adjective phrases. So in English we use the verb "to be"/"is" with adjectives: "Kawika is tall." However, Hawaiian does NOT use equational sentences for adjectives. Instead you use the adjective like it was a verb: "Lō'ihi 'o Kawika." There is no "is" verb or equational marker in this kind of sentence. "Lō'ihi" is acting like a verb and so we might even define it as "to be tall", including the verb "to be" as part of the definition of "lō'ihi" since it is used as a verb without having to use a separate verb "to be".