These words refer to an entity that takes in two or more parts or elements. Include , the most general of these, can indicate clearly defined subdivisions within a whole: The businessmen’s club includes a gym, swimming pool, sauna and locker room. It can pertain equally well to contents that are more imponderable or less tangible: a discussion that included extended treatment of the two world wars, the Korean action, and the Vietnam War. The word can be useful, since it need not suggest an exhaustive listing of parts or elements: Our ten-city tour included a visit to Stratford. Often, the word points to an additional feature, a secondary element or a side benefit: The second book was more useful because it included a detailed chronological table of the events under discussion. Comprise is a considerably more formal substitute for include , except that it most often indicates a complete or exhaustive breakdown of an entity into its parts or elements: The anthology comprises samples from the work of ten authors.

Most concretely, contain can indicate discrete things held or enclosed by a larger object: The bowl contained a variety of fruit. The word functions much like include in indicating the parts or element making up a whole. Contain , however, can function only when some sense of enclosure within the whole exists. One would not, for example, speak of a tour containing visits to various cities. Otherwise, the word compares with include and contrasts with comprise in not being restricted to an exhaustive listing.

• The book contained reproductions of paintings by Cézanne, Monet and Matisse; Does your school building contain an assembly hall?

Where both include and contain can point to concrete or material entities and their parts, involve almost exclusively concentrate on less tangible things and their elements: an argument that involved a discussion of basic principles. In this it compares with comprise ; by contrast, however, involve need not suggest an exhaustive listing: Aside from its most widely known features, his philosophical system also involved a belief in reincarnation.