8. Fill in the comparative or superlative form of the adjectives in brackets.

1. Cristiano Ronaldo is taller (tall) than Lionel Messi. 2. Michael Phelps is the fastest (fast) swimmer in the world. 3. Serena Williams is stronger (strong) than her sister, Venus. 4. Golfer Tiger Woods is richer (rich) than tennis player Roger Federer. 5. Yelena Isinbayeva is the best (good) female pole vaulter of all. 6. Grzegorz Lato is the most successful (successful) Polish footballer of all time.