Crasis (; from the Greek , "mixing", "blending") is a type of contraction in which two vowels or diphthongs merge into one new vowel or diphthong, making one word out of two (univerbation). Crasis occurs in many languages, including Spanish, Portuguese, and French; it was first described in Ancient Greek. In some cases, as in the French examples, crasis involves the grammaticalization of two individual lexical items into one. However, in other cases, like in the Greek examples, crasis is the orthographic representation of the encliticization and the vowel reduction of one grammatical form with another. The difference between them is that the Greek examples involve two grammatical words and a single phonological word, but the French examples involve a single phonological word and grammatical word. Greek In both Ancient and Modern Greek, crasis merges a small word and long word that are closely connected in meaning. In Ancient Greek, a coronis ( korōnís "curved"; plural korōnídes) marks the vowel from crasis. In ancient times, it was an apostrophe placed after the vowel (), but it is now written over the vowel () and is identical to smooth breathing in Unicode. (For instance, uses the character ; psili means smooth breathing.) Unlike a coronis, smooth breathing never occurs on a vowel in the middle of a word although it occurs in a doubled rho: pyrrhos. The article undergoes crasis with nouns and adjectives that start with a vowel: "my (affairs)" "on the contrary" "the same" (plural of the previous example) καί undergoes crasis with the first-person singular pronoun and produces a long vowel: "and I", "I too" "and to me" In the modern monotonic orthography, the coronis is not written. French In French, the contractions of determiners are often the results of a vocalisation and a crasis: de le → du, de les → des à le → au, à les → aux en les → ès (archaic) Portuguese The most frequently-observed crasis is now the contraction of the preposition a ("to" or "at") with the feminine singular definite article a ("the"), indicated in writing with a grave accent or the masculine singular definite article o (also "the"). For example, instead of *Vou a a praia ("I go to the beach"), one says Vou à praia ("I go to-the beach"). The contraction turns the clitic a into the stressed word à. Meanwhile, a person going to a bank, a supermarket