Prefix

A prefix is an affix which is placed before the stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix un- is added to the word happy, it creates the word unhappy. Particularly in the study of languages, a prefix is also called a preformative, because it alters the form of the words to which it is affixed. Prefixes, like other affixes, can be either inflectional, changing the syntactic category, or derivational, changing either the lexical category or the semantic meaning. In English, there are no inflectional prefixes; English uses suffixes instead for that purpose. Prefixes, like all other affixes, are usually bound morphemes. The word prefix is itself made up of the stem fix (meaning "attach", in this case), and the prefix pre- (meaning "before"), both of which are derived from Latin roots.

In English

List of English derivational prefixes

In English, a fairly comprehensive list, although not exhaustive, is the following. Depending on precisely how one defines a derivational prefix, some of the neoclassical combining forms may or may not qualify for inclusion in such a list. This list takes the broad view that acro- and auto- count as English derivational prefixes because they function the same way that prefixes such as over- and self- do.

Substring

A substring of a string is another string that occurs "in" . For example, "the best of" is a substring of "It was the best of times". This is not to be confused with subsequence, which is a generalization of substring. For example, "Itwastimes" is a subsequence of "It was the best of times", but not a substring.

Prefix and suffix are refinements of substring. A prefix of a string is a substring of that occurs at the beginning of . A suffix of a string is a substring that occurs at the end of .

Substring

A substring (or factor) of a string is a string , where and . A substring of a string is a prefix of a suffix of the string, and equivalently a suffix of a prefix. If is a substring of , it is also a subsequence, which is a more general concept. Given a pattern , you can find its occurrences in a string with a string searching algorithm. Finding the longest string which is equal to a substring of two or more strings is known as the longest common substring problem.

Example: The string ana is equal to substrings (and subsequences) of banana at two different offsets:

Prefix (acoustics)

In acoustics, the prefix of a sound is an initial phase, the onset of a sound quite dissimilar to the ensuing lasting vibration.

The term was coined by J. F. Schouten (1968, 42), who called it one of at least five major acoustic parameters that determine the elusive attributes of timbre.

See also

References