Humans are programmed biologically to speak, and children are pre-programmed to use receptive and expressive language as part of normal development. Written language is a human invention and an acquired skill. Speech and writing are two separate systems of signs, the sole purpose of the second is to represent the first. The Roman alphabet continues to dominate Western European languages, as the Cyrillic alphabet dominates the languages of Eastern Europe. The Anglo-Saxons had no written true representation of their language. The smallest alphabet consists of 11 letters in the Rotokas language of the Solomon Islands and the largest of 74 letters in the Khmer language spoken in Cambodia. Alphabetical skills, including visual familiarity with the symbols and their relationship to the sounds in language, are the building blocks of literacy. Difficulties with alphabetic knowledge are not manifested only in small children. Other dictionaries use the international phonetic alphabet (IPA) to provide guidelines using symbols for the sounds of any language.