Lexicalstress

Lexical stress, or word stress, is the pattern of prominence assigned to syllables within a word, most notably the position of the primary stressed syllable. It is a property of the word’s phonological form and is often stored in the mental lexicon; in many languages, the position of lexical stress is phonemic, meaning that changing the stress can alter the word’s meaning or grammatical category.

In English, lexical stress can distinguish words and word forms. For example, 'record' as a noun is RE-cord, while the verb is re-CORD; 'present' as a noun or adjective is PRE-sent, but as a verb it is pre-SENT. In other languages, stress patterns vary across words and can be predictable or irregular, contributing to the language’s phonological identity.

Languages differ in how lexical stress is determined. Some have fixed lexical stress, such as Finnish, where the primary stress almost always falls on the first syllable of a word. Others use rules based on syllable weight or word endings; for instance, in Spanish stress tends to fall on the penultimate syllable if the word ends in a vowel, 'n', or 's', and an accent mark signals irregular stress when the default rule would place it elsewhere.

Dictionaries typically indicate the stressed syllable, aiding pronunciation. Lexical stress interacts with spelling, morphology, and rhythm, and is distinguished from sentence stress, which reflects emphasis in discourse and can override or obscure the underlying lexical pattern.