A syllable is a basic unit of organization within a sequence of speech sounds, such as within a word. In phonology and studies of languages, syllables are often considered the "building blocks" of words. A syllable usually consists of a nucleus, which may be preceded by an onset and followed by a coda. Syllables may bear properties such as stress and tone and be subject to operations such as reduplication. Speech can usually be divided up into a whole number of syllables: for example, the word ignite is made of two syllables: ig and nite. Most languages of the world use relatively simple syllable structures that often alternate between vowels and consonants.