1. Sad , happy - happier; the happiest, big - bigger; the biggest, grey - grey, , far- farther; the furthest, honorable - more honorable, the most honorable, bad - worse, the worst, dry - drier, the driest, near - nearer the nearest, old - older, the oldest, complete - more complete , the most complete, unusual - more unusual, the most unusual..
2. Brilliant - more brilliant; the most brilliant, lovely, little, ugly, low, productive, heavy, strong - stronger; the strongest, slender, famous - more famous, the most famous, messy, polite - more polite, the most polite..
3. Slow - slower, the slowest, remarkable, tall- taller, the tallest., young - younger, the youngest, good - better, the best, hot - hotter, the hottest, tasty - tastier; the tastiest, cheap - cheaper; the cheapest, large - larger, the largest, high - higher, the highest, busy - busier, the busiest, many - more; the most.