The origin of "naive" is the French word "naïve". (Notice that the French "naïve" is italicized) As a French word, it is spelled naïve or naïf. (French adjectives have grammatical gender; naïf is used with masculine nouns while naive is used with feminine nouns.) The two dots above the "i" are called diaeresis. As an unitalicized English ... More @Wikipedia
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