Ako means: To learn, teach.
The example sentences on Te Aka include “Ko ngā mātauranga e akoria ana ko te reo Ingarihi, kōrero pukapuka, tuhituhi me te mapi” (The subjects being taught are English, reading writing and geography.)
This uses the preposition ‘ko’ to introduce what’s called a “fronted subject” as well as marking this subject as the topic. In any sentence, the subject can be moved to the start instead of following the predicate phrase. If it is a definite subject (generally not something using the ‘he’ preposition) then it gets introduced with ‘ko’.
So the sentence “Ka whaikōrero a Hōne ki ngā manuhiri” (Hōne will address the guests) can become “Ko Hōne ka whaikorero ki ngā manuhiri” (Hōne will address the guests) placing the emphasis on Hōne.
Another interesting property of the original sentence is that it uses a second ‘ko’ to expand on “the subjects being taught” by describing those subjects in a list. It’s common for a list of nouns to omit the determiners for later items in the list (‘kōrero pukapuka’ and ‘tuhituhi’ aren’t introduced with ‘te’).