Vocal stress

Primary stress
ˈ◌
IPA number	501
Encoding
Entity (decimal)	ˈ
Unicode (hex)	U+02C8

Secondary stress
ˌ◌
IPA number	502
Encoding
Entity (decimal)	​ˌ
Unicode (hex)	U+02CC

Extra stress
ˈˈ◌

In linguistics, and particularly phonology, stress or accent is relative emphasis or prominence given to a certain syllable in a word, or to a certain word in a phrase or sentence. This emphasis is typically caused by such properties as increased loudness and vowel length, full articulation of the vowel, and changes in pitch. The terms stress and accent are often used synonymously in this context, but they are sometimes distinguished, with accent being more strictly sound-based (auditory). For example, when emphasis is produced through pitch alone, it is called pitch accent, and when produced through length alone, it is called quantitative accent. When caused by a combination of various intensified properties, it is called stress accent or dynamic accent; English uses what is called variable stress accent.

The stress placed on syllables within words is called word stress or lexical stress. Some languages have fixed stress, meaning that the stress on virtually any multisyllable word falls on a particular syllable, such as the first or the penultimate. Other languages, like English, have variable stress, where the position of stress in a word is not predictable in that way. Sometimes more than one level of stress, such as primary stress and secondary stress, may be identified. However, some languages, such as French and Mandarin, are sometimes analyzed as lacking lexical stress entirely.

The stress placed on words within sentences is called sentence stress or prosodic stress. This is one of the three components of prosody, along with rhythm and intonation. It includes phrasal stress (the default emphasis of certain words within phrases or clauses), and contrastive stress (used to highlight an item − a word, or occasionally just part of a word − that is given particular focus).

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