Adverb and Adjective Choices in Conversation

In today’s Everyday Grammar, we will study how conversational grammar differs from written and formal grammatical structures. Americans often use adjective forms in place of adverbs. Americans also may use an adverb but choose not to say an –ly ending.

Source : https://learningenglish.voanews.com/a/adverbs-and-adjectives/3702382.html