"That is a large cup of coffee."
Translation:He kīʻaha kope nui kēlā.
You cannot translate every word like that. If you use o meaning of, then you need the requisite article after as well, ke in this case. He kīʻaha nui kēlā o ke kope. / He kīʻaha nui o ke kope kēlā.
Actually as it stands now, that sentence is a bit ambiguous. That Hawaiian could be That is a large coffee cup. or That is a large cup of coffee.
Just as in English a noun can be used as an adjective to specify the type, as a compound noun. In this case, that noun kope is used to describe what is in it.