In English and other languages there are three degrees of comparison: positive, comparative and superlative (e.g. tall, taller, tallest). Are there languages with more than three degrees, expressed morphologically?
At first, some general remarks on comparison and terminology. My answer is mostly based on Pierluigi Cuzzolin's research.
Let's start with some definition of comparison. Cuzzolin and Lehmann 2004 give the following definition:
"Taken as a grammatical category, comparison (German Steigerung) is the formal modification of some predicative word – most often an adjective – representing a parameter of gradation or comparison, according to the extent to which it applies to its argument, relative to some standard" (p. 1212).
Thus, comparison as a grammatical category includes "semantic" comparison (relative) and gradation (absolute).
Any comparison must contain at least the following three elements: the comparee, the parameter (a cognitively salient feature), and the parameter marker (a morpheme expressing a degree).
Secondly, Heine has a nice table on types of comparison. Naturally, there is some variation in terminology - but this is irrelevant here.
Cuzzolin and Lehmann 2004 argue that traditionally three degrees of comparison are recognized:
- the positive degree;
- the comparative degree, which can involve comparison of majority (smarter), comparison of minority (less smart), comparison of equality (as smart as), and even sameness (known as similative);
- the superlative degree.
Although comparison usually occurs on adjectives and adverbs, it can occur on other parts of speech, too:
Italian canzonissima 'the best song'
Basque gizonago 'more man'
The most important thing to remember about comparison is that it can be expressed by different means: morphologically, syntactically (for examples see Cuzzolin and Lehmann 2004).
Now about equative expressed morphologically (like in Welsh). Cuzzolin and Lehmann argue that it's not that common. They mention the following language groups and languages: Celtic languages, Finno-Ugric languages, Kartvelian languages, Tagalog, Indonesian, Greenlandic Eskimo, and Estonian. An example from Estonian is below:
Welsh has a distinct equative, as well as the comparative and superlative.
From the article linked to: teg "fair", teced "as/so fair", tecach "fairer", tecaf "fairest".
So mor teced â = "as fair as".