BusyTeacher contributor Susan Verner has published this useful article.
We use these adjectives to compare items, express preferences and give value judgments. Once your students have a strong grasp on adjectives, and this should happen in beginning level ESL classes, you can move their knowledge to the next level by tackling the harder world of comparatives and superlatives.
Why do we use them?
We use comparatives and superlatives to say how people or things are different.
Comparative adjectives are used to compare two people or things.
We use comparative adjectives to compare one noun to another noun. In this case, only two items are compared. For example, you can say that “the red balloon is higher than the green balloon.”