To indicate that something is better or best and vice versa, English uses 'better', 'best' and 'worse', 'worst'. These are the comparative and superlative forms of 'good' and 'bad'.

Mr. Quang Nguyen, an English pronunciation training expert, guides how to use these words:

Comparative and superlative forms of 'good' and 'bad'

Quang Nguyen (Moon ESL)