In adjectives there are two main groups:
First Group: adjectives that their 3 grades (base, comparative and superlative) are changed whether regularly (nice > nicer > nicest) or irregularly (good > better > best).
Second group: adjectives that their 3 grades, are changed by adding "more" or "most" (e.g. "more expensive" or "most expensive" rather than expensivier or expensiviest)
Then my question is how these two groups are distinguished terminologically? or in other words what are the terms for each of these two groups?
Based on some research, the terms "synthetic adjectives" (=in the first group) and "analytic adjectives" (in the second group) refer only to the comparative degree rather than to the all 3 grades together (positive, comparative and superlative adjectives) as a group. Isn't it?