When learning Japanese, one often hears the claim: "Japanese has particles, so word order is very free." This statement has its merits. "Taro ga Hanako ni hon o ageta" can also be said as "Hon o Taro ...
Happy is the main lexical predicate here. It takes one argument: an experiencer--John. Tall takes one argument: a theme: Mary. (12) *John is being tall. (13) *Mary is being fond of red roses. (14) ...