The Greeks and Romans came up with a system for creating words by putting together smaller word parts. They used three types of word parts: prefixes, suffixes, and roots. Pre means "before," and so it makes sense that a prefix comes before the main part of a word. Suf means "after," and so a suffix comes at the end of a word. A root word is the main part of a word, and usually comes in the middle. Many English words are composed of at least one root, and many have one or more prefixes and suffixes.
Word parts contribute to the total meaning of a word. Each part has its own meaning. The meaning of an unknown word often is a combination of its parts. Splitting words into parts to discover the meaning of unknown words is called structural analysis.
Parts of words provide the essential meanings. Studying the parts of words can tell you many things. The base of a word gives you an overall meaning for the unknown word. Affixes affect the base's meaning. Some affixes provide general meanings. Others identify the subject area of the unknown word. Affixes also help determine the part of speech of the unknown word.
Recognizing Word Roots and Prefixes
While using the dictionary is an excellent way to increase your vocabulary one word at a time, if you would like to learn whole clusters of words in one stroke, you should get to know the most common roots and prefixes in English.
It has been estimated that 60 percent of the English words in common use are made up partly or entirely of prefixes or roots derived from Latin and Greek. The value of learning prefixes and roots is that they illustrate the way much of our language is constructed. Once learned, they can help you recognize and understand many words without resorting to a dictionary. With one well-understood root word as the center, an entire "constellation" of words can be built up.
Although knowing the meanings of prefixes and roots can unlock the meanings of unfamiliar words, this knowledge should supplement, not replace, your dictionary use. Over the centuries, many prefixes have changed in both meaning and spelling. While some prefixes have a single and fairly invariant meaning, most prefixes have more than one meaning each.
For example, the prefix de- means "of' or "from"; yet the dictionary lists four different meanings for it. So learn as many of the common prefixes and roots as you can, but learn them for better and more precise understanding of words you already know and words that you have yet to look up in the dictionary. When you go to the dictionary, make sure that you spend some time on the prefixes and roots that make up each word. You will soon become convinced that a word is not an assemblage of letters put together like an anagram, but the true and natural outcome of evolution. (Pauk, p. 310)