The elements of English vocabulary are the morphemes that combine to make the majority of words in the English language. Morphemes are the smallest unit of sound that has meaning, such as the prefix “re-,” which adds the meaning “again” to a word. Most elements of English vocabulary come from Greek or Latin. Knowing these morphemes enables readers to understand new words simply by knowing the meaning of the word’s parts.
An example from Latin is the prefix “pre-,” which means “before.” For example, a premature baby is one that is born before he or she is mature. Presentiment, premonition, and presage all use this morpheme to signify the realization of an impending event.
The prefixes “en-,” “em-,” and “el-“ have become part of English vocabulary through Greek. Each generally means “in” or “into,” but they can also use the similar definitions of “within,” “near,” or “at.” Examples of these prefixes in action include embark and entomb. When people embark, they get into a boat or begin a journey, and when a corpse is entombed, it is put into a tomb.
Not all elements of English vocabulary are prefixes. Some, like "arch", are root words, which can have other morphemes attached to them. "Arch" is both a Latin and a Greek element, with a different definition in each. As a Latin root, it means bow or curved structure, and can be seen in words like arch and archery.
"Arch" also has a Greek definition as primary, chief, and first in importance or time, and this Greek usage is a much more common in English than the Latin. For example, anarchy is the state of government in which there is no ruler. Archaeology is the study of old things, which were first in time.
"Ped" is another element of English vocabulary with separate definitions in Latin and Greek. As a Latin root, "ped" refers to feet. Bipeds, such as humans, have two feet, and quadrupeds, such as horses, have four. When people ride a bike or drive a car, their feet push the pedals.
In Greek, "ped" refers to children. Thus, a pedagogue is a leader of children, or teacher, and a pediatric physician treats diseases in children. Neither would probably be a pedophobia, who is someone afraid of children.
While some words can be broken down into morphemes to derive meaning, this method does not work with all words. For example, a butterfly is not a stick of butter that flies and a shoehorn is not a horn in the shape of a shoe. Using affixes to derive partial meaning is fully acceptable, and correct most of the time.