Degrees of comparison
Honestly saying, I totally understood the rules of making the comparison degrees only when I started teaching. I don't know why it's not taught this way at schools and not explained in the books, it will be always a riddle for me. But it's really easy to form.
To start with, there are only 3 main rules that we should remember while forming the degrees of comparison and it's mainly refers to the syllables (слоги).
1. If the word has only 1 syllable (односложное слово) comparative degree (сравнительная степень) is formed with suffix -er and superlative degree (превосходная степень) is formed with the definite article the and suffix - est.
For instance:
big - bigger - the biggest
high - higher - the highest
2. If the word has 2 syllables (двусложное слово) AND ends with -y comparative degree (сравнительная степень) is formed with suffix -er and superlative degree (превосходная степень) is formed with the definite article the and suffix - est.
For example:
happy - happier - the happiest
If the word has 2 syllables (двусложное слово) BUT doesn't end with -y comparative degree (сравнительная степень) is formed with more+adjective and superlative degree (превосходная степень) is formed with the definite article the most+adjective.
For example:
modern - more modern - the most modern
3. If the word has 3 and more syllables (многосложное слово) comparative degree (сравнительная степень) is formed with more+adjective and superlative degree (превосходная степень) is formed with the definite article the most+adjective.
For example:
beautiful - more beautiful - the most beautiful
However there are some exceptions - words that have different way of forming degrees of comparison. You'd better remember them:
good - better - the best
bad - worse-the worst
many - more - the most
little - less- the least
far - further - the farthest