Comparison

1. ADJ

1.1. Comparative: More + ADJ

1.2. Superlative: The most +ADJ

2. ADJ

2.1. Comparative

2.1.1. ADJ + ER

2.2. Superlative

2.2.1. ADJ + THE EST

3. Spelling

3.1. Big -> Bigger -> The Biggest

3.2. Happy -> Happier -> The Happiest

4. But...

4.1. little -> less -> the least

4.2. good -> better -> the best

4.3. far -> further -> the furthest

4.4. much/many -> more -> the most

4.5. bad -> worse -> the worst