Gladys is a rich woman, but Josie is richer than Gladys, and Sadie is the richest woman in town.
The degrees of comparison are known as the positive, the comparative, and the superlative. (Actually, only the comparative and superlative show degrees.) We use the comparative for comparing two things and the superlative for comparing three or more things. Notice that the word than frequently accompanies the comparative and the word the precedes the superlative. The inflected suffixes -er and -est suffice to form most comparatives and superlatives, although we need -ier and -iest when a two-syllable adjective ends in y (happier and happiest); otherwise we use more and most when an adjective has more than one syllable.
Certain adjectives have irregular forms in the comparative and superlative degrees:
Irregular Comparative and Superlative Forms
much many some
Be careful not to form comparatives or superlatives of adjectives which already express an extreme of comparison — unique, for instance — although it probably is possible to form comparative forms of most adjectives: something can be more perfect, and someone can have a fuller figure. People who argue that one woman cannot be more pregnant than another have never been nine-months pregnant with twins.
According to Bryan Garner, "complete" is one of those adjectives that does not admit of comparative degrees. We could say, however, "more nearly complete."
I am sure that I have not been consistent in my application of this principle in the Guide (I can hear myself, now, saying something like "less adequate" or "more preferable" or "less fatal").
Other adjectives that Garner would include in this list are as follows: