2

Glyph origin
A West Arabic numeral, ultimately from Indic numerals (compare Devanagari ), from a cursive form of two lines to represent the number two. See for more.

Symbol

 * 1) The cardinal number two.
 * 2) A digit in the decimal system of numbering, as well as octal, and hexadecimal.
 * 3) A rotational symmetry element in the Hermann-Mauguin notation, indicating a rotation over π (twofold axis).
 * 4)  The two-element Boolean algebra, two-point discrete space or a (canonical) two-element set.
 * 5)  The square of a number or a unit.
 * m2 stands for square meter.
 * $n^{2}$ is usually pronounced as "n squared".
 * 1)  the pitch of a tone, whose value depends on local convention (e.g. nearly as high or as low as 1, if four or more numbers are used; mid pitch if the numbers 1–3 are used; or contrasting with 1 if only '1' and '2' are used)
 * , depending on other values
 * 1)  tone number 2, typically identified with light level yang ping (陽平). May be identified with rising shang tone (上) if the yin–yang distinction is not made.
 * 2)  accent 2 in Norwegian, Swedish and Limburgish.
 * Norwegian/Swedish toneme 2 has also been transcribed with a double stress mark, that is ⟨ˈˈ⟩, as well as ⟨ˇ⟩, ⟨˟⟩ and ⟨ˆ⟩.
 * Norwegian/Swedish toneme 2 has also been transcribed with a double stress mark, that is ⟨ˈˈ⟩, as well as ⟨ˇ⟩, ⟨˟⟩ and ⟨ˆ⟩.

Alternative forms
The following forms are equivalent as a decimal digit:

The following additional forms are equivalent as a cardinal number:

Preposition

 * I have 2 go now. / Send files 2 him.
 * 1)   designating conversion from one format to another
 * pdf2txt, i.e. conversion from PDF to plain text
 * pdf2txt, i.e. conversion from PDF to plain text

Adverb

 * Can I come 2?
 * Can I come 2?

Usage notes
This is usually used to indicate that an affix or clitic varies between using the back vowel and the front vowel.