Notes on vocabulary: Forms like"agól bainne" mean literally "at drinking milk", and the word "bainne" is in the genative or possessive case, as mentioned in Lesson 20. Often this case form is similar to the nominative case, which is the form that you have been learning. Sometimes there is more change, as in "beoir" (BYOH-ir), beer. It becomes "beorach" (BYOH-ruhk*), of beer, in the genitive.
The nouns can be grouped in dependence on how their genitive case and plurals are formed. We will be doing some of this in the next lessons, using phrases as much as possible. You will learn how to work out what the forms should be for many nouns.