Finnish orthography is based on the Latin script, and uses an alphabet derived from the Swedish alphabet, officially comprising twenty-nine letters but also including two additional letters found in some loanwords. The Finnish orthography strives to represent all morphemes phonologically and, roughly speaking, the sound value of each letter tends to correspond with its value in the International Phonetic Alphabet (IPA) – although some discrepancies do exist.
The following table describes how each letter in the Finnish alphabet (Finnish: Suomen aakkoset) is spelled and pronounced separately. If the name of a consonant begins with a vowel (usually ä [æ]), it can be pronounced and spelled either as a monosyllabic or bisyllabic word. In practice, the names of the letters are rarely spelled, as people usually just type the (uppercase or lowercase) glyph when they want to refer to a particular letter.
The pronunciation instructions enclosed in slashes are broad transcriptions based on the IPA system. In notes, more narrow transcriptions are enclosed in square brackets.
In addition, w is sometimes listed separately and after v, although officially it is merely a variant of the latter and can be alphabetized as v. Similarly, š and ž are variants of s and z, but they are often overlooked, as they are only used in some relatively new loanwords and foreign names, and may be replaced with sh and zh, respectively, if it is technically impossible to reproduce š and ž. The Finnish keyboard layout on Microsoft Windows does not include š or ž; thus, in practice, only highly formal sources such as official texts, encyclopedias or Helsingin Sanomat use them.
The main peculiarities in the Finnish alphabet are the two extra vowel letters ä and ö (accompanied by the Swedish å, which is actually not needed for writing Finnish). In Finnish, these extra letters are collectively referred to as the ääkköset when they need to be distinguished from the ISO basic Latin alphabet; the word is a somewhat playful modification of aakkoset, which is the Finnish for the alphabet as a whole.