Circumflex Explained

The circumflex (ˆ) is a diacritic used in the written forms of many languages, and is also commonly used in various romanization and transcription schemes. It received its English name from Latin circumflexus (bent around)—a translation of the Greek περισπωμένη (perispōménē). The character is also used in mathematics, where it is typically called hat or roof.

For actually adding the diacritic to a base letter (as in), Unicode has . In addition, the ISO-8859-1 character encoding includes the precomposed characters â, ê, î, ô, û (as well as their respective capital forms), and dozens more are available in Unicode.

There is a similar but larger character,, which is also included in ASCII but often referred to as caret instead. It is, however, unsuitable for use as a diacritic, as it is a spacing character. Another spacing circumflex character in Unicode is the smaller, mainly used in phonetic notations.



See also: Ancient Greek accent. In the polytonic orthography of Ancient Greek, the circumflex marked long vowels that were pronounced with high and then falling pitch. Its shape was originally a combination of the acute and grave accents (^), but later a variant similar to the tilde (~) was also used.

The circumflex marked a syllable contracted from two vowels: an acute-accented vowel and a non-accented vowel. Because all non-accented syllables were once marked with a grave accent, the contracted syllable was marked by the acute and grave combined. This combination became the circumflex.

nóòsrowspan=2 style="width: 8em;"contraction
nóùs = ns (noũs)
νόὸςνόὺς = νοῦς

The term is also used to describe similar tonal accents that result from combining two vowels in related languages such as Sanskrit and Latin.

Since Modern Greek has a stress accent instead of a pitch accent, the circumflex has been replaced with an acute accent in the modern monotonic orthography.


The circumflex accent marks a long vowel in the orthography or transliteration of several languages.


The circumflex accent marks the stressed vowel of a word in some languages:


The circumflex is also used to indicate the relative height of some vowels:



As ever, there are exceptions, such as

Some homophones (or near-homophones in some varieties of French) are distinguished by the circumflex, for instance cote ("level", "mark") and côte ("rib" or "coast"). The letter ê is normally pronounced open, like è. In the usual pronunciations of central and northern France, ô is pronounced close, like eau; in Southern France, no distinction is made between close and open o. See also Use of the circumflex in French.



Letter extension

Other regular uses

Exceptional use


In mathematics, the circumflex is used to modify variable names; it is usually read "hat", e.g. î is "i hat". The Fourier transform of a function ƒ is often denoted by



In the notation of sets, a hat above an element signifies that the element was removed from the set.

In vector notation, a hat above a letter indicates a unit vector (a dimensionless vector with a magnitude of 1). For instance, î stands for a unit vector in the direction of the x-axis.

In statistics, the hat is used to denote an estimator or an estimated value, as opposed to its theoretical counterpart. For example, in errors and residuals, the hat in ε̂ indicates an observable estimate (the residuals) of an unobservable quantity called ε (the statistical errors). It is read x-hat or x-roof, where x represents the character under the hat.

See also


  1. Book: Pravopis Srpskog Jezika. Genitivni znak. Serbian.

External links