Metrical phonology is a notation for phonological constituency which permits binary branching only and in which sister nodes are labelled [S W] or [W S] (where S stands for 'stronger than W' and W for 'weaker than S'). The labels S and W are not labels in the sense current in other constituency notations: they have no local interpretation. The only possible interpretation of a node is one in relation to its sister: a node is stronger or weaker than its sister and no other possibility of interpretation exists. A metrical tree contains two hierarchies: the hierarchy of phonological constituents and a hierarchy of relative prominence. Given the template of metrical phonology, or any other device of other notational systems, principles of syllable boundary placement are provided independently by phonological theory. The metrical structure is an almost exact copy of the syntactic surface structure — the only deviation being that go forms a foot that spreads across a syntactic boundary.