What part of speech is confident when used in a simple sentence like She is confident. Is confident a noun or an adjective. I think it can be both - an adjective as in 'She is a confident girl' or a noun as confident is the object of 'is'.
NOT A TEACHER
Confident is always, as far as I know, an adjective. In the sentence: 'She is a confident girl', the indefinite article belongs to the noun 'girl' and no to the adjective 'confident'. Therefore you can't say 'She is a confident'. The object of 'is' is the whole phrase 'a confident girl'.