An elision removes a letter or letters in a word in order to reduce the number of syllables or to blend words together. The missing letter is usually replaced with an apostrophe. Normally used intentionally, elisions are seen frequently in certain poetry in order to maintain a set meter, such as iambic pentameter. It is also used in many languages to shorten words or make certain pairs of words more easily said. Additionally, it is employed in speech when the pronunciation of words is abbreviated or slurred.
In poetry that requires a specific meter, or a specific number of stressed syllables in each line, elision is commonly employed. Generally used to remove a letter from the end or middle of a word, elision may blend two words together or eliminate a syllable from a single word. When blending two words the first word must end with a vowel and the second must begin with one, as in "th' expanse" for "the expanse." If a letter is removed from the middle of a word, the letter may be a constant or a vowel, such as "ne'er" for "never" or "op'ning" for "opening."
Many languages use elision to shorten or blend more than one word in order to improve the flow of sentences or speed up speech. Contractions are one of the most well known examples of elisions, such as in "won't" to stand for "will not" in English. Both "won't" and "will not" are grammatically correct, although in certain formal writing contractions are discouraged.
In other languages, however, elisions are required. For example, in French certain words are blended together to improve the flow. If a word, usually a pronoun or article, ends with an "e" or an "a" and the proceeding word begins with a vowel, the "e" or "a" in the first word is dropped and the two words are connected with an apostrophe. For example, The French word for "I" is "je" and the first person spelling for the verb "to have" is "ai." Writing, or saying, "je ai," however, is grammatically incorrect. Instead, the elision must be used: "j'ai."
Although elisions usually indicate the loss of a letter or letters by an apostrophe, not all instances do. Elisions used in speech as a result of a dialectic or rushed pronunciation often simply mesh the words together. When these types of elision are seen in writing, they often are represented by new words or have no change in the written spelling at all. For example, the word "mathematics" is often shortened to omit the middle "e" sound when spoken, but is still written to include it. Alternately, the phrase "I don't know," which already contains an elision, may be further shortened in speech into "I dunno."