There are two forms of the reduplication of the adjectives, including AABB such as gāogāo-xìngxìng 高高兴兴 and ABAB gāoxìng-gāoxìng 高兴高兴。While words in the form of AABB are generally adjectives and function as verb phrases in the form of ABAB. For example,
他高高兴兴地上学了
Tā gāogāoxìngxìng de shàngxué le
He happily go to school
‘He cheerfully went off to school.’
Kuài gàosù tā zhège hǎo xiāoxi, rang tā gāoxìnggāoxìng
Immediately tell him this good news make him happy
‘Tell him the good news as soon as possible to make him happy.’
引自——彭小川,李守纪,王红. 对外汉语教学语法释疑201例. 北京:商务印书馆,2004.