In some cases, the answer is clear and well-known. We know that Spanish is simply a later version of the Latin language that was spoken in Rome two thousand years ago. Latin spread with the Roman conquest of Europe and, following the breakup of the Roman Empire, the regional dialects of Latin gradually evolved into the modern Romance languages: Sardinian, Rumanian, Italian, French, Catalan, Spanish, and Portuguese. A language family , such as the Romance family, is a group of languages that have all evolved from a single earlier language, in this case Latin.

	Table 1 . A Simple Example of Language Similarities
	Language		"Hand"
	English Danish German		hænd haand hant
	Russian Polish Serbo-Croatian		ruka r ka ruka
	Spanish Italian Rumanian		mano mano
	The words in the second column are written in the International Phonetic Alphabet

But while the Romance family illustrates well the concept of a language family, it is also highly unusual in that the ancestral language — Latin — was a written language that has left us copious records. The usual situation is that the ancestral language was not a written language and the only evidence we have are its modern descendants. Yet even without written records, it is not difficult to distinguish language families, as can be seen in Table 1 . Here similarities among certain languages in the word for "hand" allow us to readily identify not only the Romance family (Spanish, Italian, Rumanian), but also the Slavic family (Russian, Polish, Serbo-Croatian) and the Germanic family (English, Danish, German). There are, however, no written records of the languages ancestral to the Germanic or Slavic languages, so these two languages — which must have existed no less than Latin — are called Proto-Germanic and Proto-Slavic, respectively.