the language that is replaced (known as the substratum) can leave a profound impression on the replacing language (known as the superstratum) when people retain features of the substratum as they learn the new language and pass these features on to their children, which leads to the development of a new variety. For example, the Latin that came to replace local languages in present-day France during Ancient Rome times was influenced by Gaulish and Germanic. The distinct pronunciation of the Hiberno-English dialect, spoken in Ireland, comes partially from the influence of the substratum of Irish. Outside the Indo-European family, Coptic, the last stage of ancient Egyptian, is a substratum of Egyptian Arabic. Creation of new languages: creolization and mixed languages Language contact can also lead to the development of new languages when people without a common language interact closely. Resulting from this contact a pidgin may develop, which may eventually become a full-fledged creole language through the process of creolization (though some linguists assert that a creole need not emerge from a pidgin). Prime examples of this are Aukan and Saramaccan, spoken in Suriname, which have vocabulary mainly from Portuguese, English and Dutch. A much rarer but still observed process, according to some linguists, is the formation of mixed languages. Whereas creoles are formed by communities lacking a common language, mixed languages are formed by communities fluent in both languages. They tend to inherit much more of the complexity (grammatical, phonological, etc.) of their parent languages, whereas creoles begin as simple languages and then develop in complexity more independently. It is sometimes explained as bilingual communities that no longer identify with the cultures of either of the languages they speak, and seek to develop their own language as an expression of their own cultural uniqueness. Dialectal and sub-cultural change Some forms of language contact affect only a particular segment of a speech community. Consequently, change may be manifested only in particular dialects, jargons, or registers. South African English, for example, has been significantly affected by Afrikaans in terms of lexis and pronunciation, but the other dialects of English have remained almost totally unaffected by Afrikaans other than a few loanwords. In some cases, a language develops an acrolect that contains elements of a more prestigious language. For example, in England during a large part of the Middle Ages, upper-class speech was dramatically influenced by French to the point that it