I feel as though I may finally have cracked the code for adjective inflection, thanks to canoo.net. For each word, they supply the various forms that the word may take. For adjectives these are the positive, comparative and superlative forms and the three inflection classes for each of these. Why three classes? Because in addition to gender, number, and case, German requires different inflections based on whether there is no article, a definite article or an indefinite article. These are respectively the strong, weak and mixed inflectional forms and it is these names that now begin to make sense.
The strong or stark inflection is the most varied. For each gender and for the plural form, there are three different forms. However, because there is some overlap, there are only five forms in total. That’s still a lot to remember, hence one needs to be “strong” or “do some heaving lifting” memory-wise when going without an article.
The weak or schwach inflection is the least varied. Each gender takes only two forms and these two forms are the same for all of them – an “e” or an “en” ending. The plural has only one form – an “en” ending. To stay with the idea of heft, two is less than five, thus less “strength” is needed to “pick up”these forms (assuming, of course, that one has mustered the strength to commit the definite articles to memory).
Finally, in the mixed inflection each gender has just two forms, however these vary between them and therefore there are four forms in total (the plural has only one form). For the feminine and the plural, the forms are identical to those of the weak inflection – “e” and “en” endings for the feminine and the “en” for the plural. For the masculine, the ending in the nominative case is “r” and for the neutral, the ending in the nominative and accusative cases is “s” – just as they were with the strong inflection. In the other cases the ending is “en.” In my mind’s eye, I see some barbells. The masculine one has a single weight on one side and three on the other; the feminine and neutral have two weights on each side; and the plural has all of the weights in the middle since it takes only one form.