The notion of the foot originates from the study of poetic rhythm. Rhythm refers to the repetition of an alternation, and the foot refers to the unit of repetition in poetic rhythm, whose unit is usually an alternation between a strong syllable and a weak one. Therefore, the most common foot consists of a strong beat (S) and a weak one (W). In generative phonology, the foot is also used to analyze word stress. Previous studies tend to assume a typological approach, according to which different poems can have different rhythms and different feet. It is also assumed that rhythm itself can be based on different phonetic properties, such as alternations in syllable length, in stress, or in tone. After examining occurring and non-occurring poetic rhythms in English, Chinese, and Japanese, it is found that all the rhythms can be accounted for by a single foot type, although it is hard to determine whether it is WS (an iamb) or SW (a trochee). Further examination of occurring and non-occurring patterns of word stress in various languages shows that a single foot type is again sufficient, and SW is superior to WS.

San Duanmu is Professor of Linguistics, University of Michigan. He received his PhD in Linguistics from MIT in 1990 and has held teaching posts at Fudan University, Shanghai (1981-1986) and the University of Michigan, Ann Arbor (1991-present). His research focuses on general properties of language, especially those in phonology. He is the author of The phonology of Standard Chinese (2nd edition, Oxford 2007), Syllable Structure: The Limits of Variation (Oxford 2008), and A Theory of Phonological Features (Oxford 2016).