Abstract: A word is abstract if it refers to an item that cant be apprehended by one of the five senses. For example, an idea or concept like justice is abstract. Also, an emotion like fear is abstract. You might argue that you can see fear on a persons face, but what you actually see is a particular expression such as mouth open and eyes wide that you have come to associate with the internal emotion of fear. Since you cannot see or hear directly another persons thoughts or feelings, those thoughts and feelings are abstracts. This is not to say that abstracts are not real. A persons fears may indeed be real, but they are nonetheless abstract. Abstracts, because another person has no direct sense access to them, are best supported in writing by using concrete items as descriptions and examples.

Concrete: A word is concrete if it refers to an item that can be apprehended by one of the five senses. For example, the word dog is concrete because it refers to an item that you can see, hear, touch, etc. Because concrete items can be more easily visualized or imagined directly, a reader understands them more easily.

General: A word is more general than another word if it somehow "contains" the other word and more besides. For example, the word mammal is more general than the word dog because mammal can mean dogs, but it can also mean cats, horses, cows, mice, and many others besides. The word dog is more general than the word cocker spaniel because dog can mean cocker spaniel, but it can also mean beagle, terrier, bulldog, or many others. In summary, a word is not general in itself, but only when compared to another word.

Specific: A word is more specific than another word if the other word somehow "contains" it as well as others. For instance, the word dog is more specific than mammal because dog is contained by mammal. Beagle is more specific than dog because it is contained by dog. Because more specific words are harder to misunderstand than more general words, it is usually better for a writer to be as specific as possible. When a writer has made the word as specific as possible, adding other kinds of description serve to make things even more specific. For example, red brick house is more specific than brick house. A word is not specific in itself, but only in comparison to another word.

As a rule of thumb, writers are advised to deal with abstractions carefully and with the use of concrete descriptions or examples. All concrete descriptions and examples should be as specific as possible.