Chapter 3 introduces lower-level constituents of the prosodic hierarchy – mora and syllable. The syllable structure is discussed from different perspectives: the role played by the sonority hierarchy and the phonotactic restrictions it imposes on sequences of segments in the syllable; the individual positions such as onset, nucleus, coda as well as prefix and appendix; and the weight of individual segments expressed in moras, leading to relative weight of the syllable itself. It is shown that the number of segments allowed in each position is strictly fulfilled. As for the weight properties of syllables, lax vowels are monomoraic, tense vowels are bimoraic and schwa is non-moraic. The syllable itself can be non-moraic, bimoraic or trimoraic. The chapter ends with a detailed proposal on how ranked OT constraints can account for the sonority sequencing among the segments as well as the restrictions observed in the number of segments that can fill the different syllable constituents. The second part of the OT analysis focuses on the moraic constituency of the segments of a syllable.