Answer:
1) happiest
2) best
3) most popular
4) worst
5) prettiest
Explanation:
An adjective is a word that describes a noun. The degrees of adjectives are positive, comparative, and superlative.
The superlative degree of adjective is the highest degree of adjectives.
These are the answers to the questions asked.
1) It was the happiest day of my life.
This is because the superlative form of " happy" is "happiest"
2) It's the best film I've ever seen.
The superlative form of "good" is "best"
3) She's the most popular singer in the country.
The superlative form of "popular"is "most popular"
4) It was the worst I've ever made.
The superlative form of "bad" is "worst"
5) It's the prettiest I've ever seen
The superlative forms of "pretty" are "prettiest" and "most pretty"