Linguistic Features:
* Shared Vocabulary: While the individual languages have diverged significantly, they retain a core vocabulary reflecting their common ancestry. This includes cognates (words with shared origins) relating to basic concepts like family, body parts, and natural phenomena.
* Grammatical Structures: Celtic languages exhibit several unique grammatical features not found in many other Indo-European languages. These include:
* Vowel mutations: Changes in vowels within words, often marking grammatical function (e.g., singular vs. plural).
* Initial consonant mutations: Changes in the initial consonant of a word, again often marking grammatical function.
* Synthetic morphology: Information about grammatical relations (such as tense, aspect, and case) is often encoded within the word itself, rather than relying heavily on word order.
* Verb systems: Complex verb conjugations reflecting intricate systems of tense, aspect, mood, and voice.
* Sound Changes: Celtic languages have undergone specific sound changes over millennia, differentiating them from other Indo-European branches.
Content (Culture and History Reflected in the Languages):
* Mythology and Folklore: Celtic languages preserve elements of ancient mythology and folklore in their vocabulary, place names, and literature. Many words relate to supernatural beings, ritual practices, and traditional stories.
* Social Structures: The languages reflect the social structures and kinship systems of past Celtic societies. Vocabulary related to family roles, social status, and political organization provides valuable insights.
* Environment and Landscape: Extensive vocabularies describe the natural environment, flora, fauna, and landscapes where Celtic speakers lived. This gives clues to their historical geography and interaction with nature.
* Technology and Material Culture: Words for tools, crafts, and other aspects of material culture illustrate the technological advancements and daily life of Celtic peoples.
* Literature and Poetry: Though much ancient Celtic literature is lost, surviving texts in languages like Irish and Welsh offer rich insights into their history, beliefs, and artistic expression.
Challenges in Understanding:
It's important to note that the Celtic languages are not monolithic. They've diversified into several distinct branches (Insular Celtic, Continental Celtic), with further subdivisions (e.g., Goidelic – Irish, Scottish Gaelic, Manx; Brittonic – Welsh, Breton, Cornish). The extent of mutual intelligibility between these languages varies greatly. Moreover, many Celtic languages are endangered or extinct, making their study challenging.
In summary, "what's in" the Celtic languages is a vast tapestry of linguistic features, cultural heritage, and historical information, woven together through centuries of evolution and transmission. They provide invaluable insights into the history and culture of the Celtic peoples and the Indo-European language family as a whole.