This English grammar lesson summarizes the progressive comparison of adjectives.
Adjectives which take endings
In the case of adjectives which take endings, the comparative form of the adjective is repeated in a progressive comparison.
Subject + linking verb + adjective which takes endings + and + adjective which takes endings
My mother became angrier and angrier.
It got hotter and hotter.
She is becoming prettier and prettier.
More and More
However, comparative adjectives that use more, we simply repeat the word more.
Subject + linking verb + more + and + more + comparative adjective that use more
The technology became more and more innovative.
People grew more and more restless.
He became more and more ambitious.
Less and Less
We use less and less for both adjectives which take endings and comparative adjectives that use more.
Subject + linking verb + less + and + less + adjectives which take endings/comparative adjective that use more
The noise is getting less and less loud. (=The noise is getting decreasingly loud.)
The relationship grew less and less exciting. (=The relationship grew decreasingly exciting.)