This article focuses on the comparative analysis of the adjective in the Romance languages (on the basis of the Spanish, Portuguese, Italian and French). The author analyzes the scientific works and makes a comparative analysis of the adjective in the Romance languages. He also demonstrates the possibility of simultaneous learning of Spanish, Portuguese, Italian and French based on the lexical and grammatical similarities of these languages. The author compares the formation masculine and feminine adjectives, plural adjectives and the cases of usage of the adjective.