Tilde

The tilde is a variable-use diacritic.

Unicode recognizes the following precomposed tilde-appended letters: ã ẽ ĩ ɫ ñ õ ũ ṽ ỹ

The two most common uses originate from the Iberian peninsula:

• Nasalization
  • Portuguese marks its nasal vowels by ã õ (from older aⁿ oⁿ).
  • Inspired by this, the IPA marks nasalization of any segment with a superscript tilde, as in [ã].
  • Several other nat- and conlangs follow suit.
• Palatalization
  • Spanish ñ (from older nn) represents a palatal nasal /ɲ/.
  • This has also been adpoted for Basque.

Other uses include:

• Emphasis
  • Older IPA standards use a middle tilde for velarization or pharyngealization. This still survives in ɫ.
  • Transcription of Quenya uses ñ to represent a velar nasal /ŋ/.
• Derounding: Estonian uses õ to represent a close-mid back unrounded vowel /ɤ/.
• Tone: Falling tone in ancient Greek is sometimes marked with a tilde (the usual diacritic is circumflex).