For the sake of sparing your fingers in case you're here to ask what the difference is between Ka, Ke and Nā :
Ka, Ke and Nā are determiners [definite articles] that all mean "The".
Use ke when the noun that follows begins with the letters K, E, A, or O.
Use ka with almost all others!
Warning: There will be exceptions (don't worry, we'll let you know which ones they are!).
Nā is only used to say "The" when the noun is plural.
Certain words like "Wahine" [Woman] are pronounced with a longer "ā" when plural and hence spelled with a kahakō (macron), "wāhine".
Kēlā and Kēnā both mean "That". The difference is kēlā refers to "That" which is away from the listener and kēnā refers to "That" which is near the listener.
Cultural note of interest: Hawaiians are keenly aware of space and time.
Note: Everything in square brackets are my notes.
Quoted from the Tips and Notes for this lesson. AP4418
Either that, or "the" should not exist as a separate entry, but only in connection to another word, so that the distinction between them is kept clear. The German course doesnʻt have distinct entries for der, die, das, den, dem, etc. Nor does the Portuguese course have o/a as distinct entries.
I agree that all three of the words ( ka ke na) that mean the should be acceptable BUT this app always says how most people use it, which means it should be good. What I'm saying is that if so many people want to use Dualingo, they want to make sure you get the best learning experiance, teaching you when to use the right articles to improve your knowledge. And who wants to go to Hawaii and talk to the people using incorrect words? That's what this app is trying to prevent.