Articles: Declension

The good thing about articles in Greek is that

There is only one kind: the definite article, which is used much more than it is in English. And which, unlike the English the, always gives a lot of information about the noun it refers to:
- What gender is that noun?
  Gender in English nouns is sex-related:
  all men and boys are masculine "he"
  all women and girls are feminine "she"
  all other nouns are neuter "it", (except when we personalize them: ships, cars maybe, sometimes countries etc.)
  But in Greek - like in French, German, Russian, Latin.... gender of nouns is word-related. Man (and male animals) are still masculine, women (and most animals, unless specified as male) are still feminine, but other words, like sun, moon, stars, trees, virtues and vices, thoughts and feelings etc. can be masculine or feminine or neuter.
- What case is it? Thanks to the article we know immediately whether an unknown word is genitive, dative, accusative, singular or plural, whichever the declension of that word.
There are very few forms to remember, and those forms give us the endings of 1st (feminine) and 2nd (masculine/neuter) declension nouns (after dropping the initial τ of course).