text: Ogonek (ą), used in Lithuanian to indicate long vowels.
  Trema (ä), used in Aymara to indicate long vowels.
  Additional letters
  Vowel doubling, used consistently in Estonian, Finnish, Lombard, Navajo and Somali, and in closed syllables in Dutch, Afrikaans, and West Frisian. Example: Finnish tuuli  'wind' vs. tuli  'fire'.
  Estonian also has a rare "overlong" vowel length but does not distinguish it from the normal long vowel in writing, as they are distinguishable by context; see the example below.
  Consonant doubling after short vowels is very common in Swedish and other Germanic languages, including English. The system is somewhat inconsistent, especially in loanwords, around consonant clusters and with word-final nasal consonants. Examples:
  Consistent use: byta  'to change' vs bytta  'tub' and koma  'coma' vs komma  'to come'
  Inconsistent use: fält  'a field' and kam  'a comb' (but the verb 'to comb' is kamma)
  Classical Milanese orthography uses consonant doubling in closed short syllables, e.g., lenguagg 'language' and pubblegh 'public'.
  ie is used to mark the long  sound in German because of the preservation and the generalization of a historic ie spelling, which originally represented the sound . In Low German, a following e letter lengthens other vowels as well, e.g., in the name Kues .