Aristotelian logic is more like an English lesson: one subject and one predicate are used in a sentence (called a proposition). The subject is usually an individual entity (an object, house, city, man, animal); or it may be a class of entities (objects, houses, cities, men, animals). The predicate is the property or mode of existence that does or does not exist with a given subject. For example, a singular plant (subject) may or may not be blooming (predicate); all houses (subject) may or may not have two stories (predicate).