Initial consonant mutation is a phenomenon common to all Insular Celtic languages (there is no evidence of it in the ancient Continental Celtic languages of the early first millennium). The first consonant of a word in Welsh may change depending on grammatical context (such as when the grammatical object directly follows the grammatical subject), when preceded by certain words, e.g. , , and or when the normal word order of a sentence is changed, e.g. , "I have a house".
