In linguistics, a conservative form, variety, or modality is one that has changed relatively little over its history, or which is relatively resistant to change. It is the opposite of innovative or advanced forms or varieties, which have undergone relatively larger or more recent changes.
A conservative linguistic form, such as a word, is one that remains closer to an older form from which it evolved, relative to cognate forms from the same source. For example, the Spanish word caro and the French word cher both evolved from the Latin word cārum. The Spanish word, which is more similar to the common ancestor, is more conservative than its French cognate.
A language or language variety is said to be conservative if it has fewer innovations (in other words, more conservative forms) than related varieties do. For example, Icelandic is, in some aspects, more similar to Old Norse than other languages that evolved from Old Norse, including Danish, Norwegian, or Swedish, while Sardinian is regarded by many linguists to be the most conservative Romance language. Therefore, Icelandic and Sardinian are considered relatively conservative languages. Likewise, some dialects of a language may be more conservative than others. Standard varieties, for example, tend to be more conservative than non-standard varieties, since education and codification in writing tend to retard change.
Writing is generally said to be more conservative than speech. That is to say that written forms generally change more slowly than the spoken language does. This helps explain inconsistencies in writing systems such as that of English; since the spoken language has changed relatively more than the written language has, the match between spelling and pronunciation is inconsistent. (See Great Vowel Shift)