Vowel whose quality does not change over the duration of the vowel is called a monophthong. Monophthongs are sometimes called "pure" or "stable" vowels. A vowel sound that glides from one quality to another is called a diphthong, and a vowel sound that glides successively through three qualities is a triphthong. All languages have monophthongs and many languages have diphthongs, but triphthongs or vowel sounds with even more target qualities are relatively rare cross-linguistically. English has all three types: the vowel sound in "hit" is a monophthong , the vowel sound in "boy" is in most dialects a diphthong , and
Types of rape Types of rape Rape can be categorized in different ways: for example, by reference to the situation in which it occurs, by the identity or characteristics of the victim, and by the identity or characteristics of the perpetrator. These categories are referred to as types of rape. The types of rape described below are not mutually exclusive: a given rape can fit into multiple categories, by for example by being both a prison rape and a gang rape, or both a custodial rape and the rape of a child. The term "date rape" is used to refer to several types