Tildes

Tildes are diacritical marks in the form of a small wavy line placed above or through letters in various languages. The term comes from the Spanish word tilde. Tildes serve different purposes depending on the language, most commonly indicating a change in pronunciation, but they can also denote nasalization, tone, or to create a distinct letter such as the letter ñ.

In Portuguese, tilde marks nasal vowels on letters such as ã and õ, signaling nasalization and affecting vowel quality; in Spanish, the tilde is used to form the letter ñ, representing a palatal nasal sound. In Vietnamese, the tilde diacritic is used as one of several tone marks on vowels, notably the ngã tone, which alters pitch and contour.

In computing and typography, the tilde character itself (~) is a separate symbol. It is commonly used to indicate approximation (as in "about 5 ~ 6") and, on Unix-like systems, to denote a user's home directory. It also serves as a shorthand for various linguistic and mathematical conventions.

Unicode provides both precomposed tilde letters such as ñ (U+00F1), ã (U+00E3), and õ (U+00F5), as well as a combining tilde diacritic (U+0303) that can be applied to any base letter. Input methods and fonts vary, which can affect how tilde letters render in different systems.