If you mean singular abstract nouns, that is an abstract noun that is a word for one thing; for example, one idea, one question, one situation, etc. An abstract noun is a word for something that can't be experienced by any of the five physical senses; something that is known, learned, thought, understood, or felt emotionally. There are some abstract nouns that are count nouns (nouns that have a singular or plural form) and some abstract nouns are uncountable nouns (nouns that have only a singular or a plural form). Additional examples of singular abstract nouns are: