As an adjective, the phrase all right can mean satisfactory or agreeable. It can also mean safe or well. And, informally, it can mean good ….
In terms of nouns at least, English is pretty regular. The vast majority of nouns in English form the plural by simply adding either –s ….
I am a man of a particular age. Seasoned, let’s say. I remember the eldest son of the great World Boxing Heavyweight Champion Maximilian Adelbert ….