The Yiddish language is written with the Hebrew script in keeping with Jewish tradition. While an abjad with very little vowel representation is perfectly suited to Semitic languages such as Hebrew, some tinkering is required to shape it around the vastly different phonemic aspects of a Germanic language. There is no true standardized orthography for Yiddish, however the most widely used standard is that produced by the Yidisher Visnshaftlekher Institute. This system combines traditional spelling of Hebrew or Aramaic words with their vowels removed and psuedo-phonetic spelling designed to bridge gaps between the myriad of Yiddish dialects (in other words, the spelling's recognizably phonetic, but no native speaker of the language pronounces it entirely as it is written).

Compromises to facilitate phonemic spelling are various. For example, several characters are combined in diagraphs to represent common sounds such as zayen-shin (זש) for 'zh' or tes-shin (טש) for 'tsh'. Characters preserve their unique final forms when they exist. Several characters do not represent any sound of Germanic origin and are used only for Semetic words. Some of these characters are duplicates of their Germanic equivalents. The aleph has the most variations from standard Hebrew, being used with diacritics to represent the vowels 'a' and 'o' as well as serving without diacritic to prefice silently any other vowel at the beginning of a word. Yiddish is written from right to left, which makes it rather odd to read even though reversing the letters will cause it to look recognizable to a German speaker.

Daniels, Peter T., Bright, William. The World's Writing Systems. Oxford: Oxford University Press, 1989.
YIVO Institute for Jewish Research.