These words are alike in referring to conditions or things having actual presence or reality. Exist and be (here considered only as a substantive verb) are interchangeable when a flat assertion of reality is intended: God exists ; God is . Of the two, be is the more forceful, carrying the weight of intense personal conviction; exist has a more detached connotation, more often suggesting that a record is simply being made of observable or otherwise known phenomena. In other senses exist and be are not commonly interchangeable. Exist can mean to continue to be : are not commonly interchangeable. Exist can mean to continue to be : Animals cannot exist without oxygen. Be can be used to designate that something exists in a particular place or time: There are bears in the zoo.

Live means to have life, to function as an animate organism: There dazed survivor of the collision asked whether his brother was living or dead. Live is commonly used to mean to continue in existence, to remain alive, and in this sense is sometimes interchangeable with exist : Animals cannot live (or exist ) without oxygen. But when it refers to a particular place or time, it parallels be .

• Kangaroos live in Australia; There are Kangaroos in Australia.

Subsist , which has the etymological meaning of to stand under, means to maintain one’s existence or mange to live , and often suggests a relation between existence or life and the conditions which support it: For three months the stranded sailors subsisted solely on indigenous plants and an occasional fish washed ashore. Although either exist or live could be used in the foregoing example, subsist emphasizes the dependence of life on the conditions described more strongly than either of the other words. Subsist is less commonly and more formally used today to refer to anything that has existence or reality, or that continues to exist : beauty that subsisted in the brilliantly conceived concordance between colour and form within the painting. Even here a contingent relation is suggested.