The adverb yòu (又/ one more time) depicts the accumulation of relevant properties of the same entity or accumulation of similar events.
他來了又來 (t¯a l´ai le y`ou l´ai/ He came again and again.)
他試了一次又一次 (tā shì le yī cì yòu yī cì/ He tried again and again.)
In these examples, the event of "來了/試" is accumulated. Moreover, it is worth noticing that the accumulated event must have been actualized.
他又會唱歌又會跳舞 (t¯a y`ou hu`ı ch`ang g¯e y`ou hu`ı ti`ao w˘u/ He can sing and dance.) → In this example, another skill "跳舞" is accumulated as one of his talents.
Reference: Chinese: a linguistic introduction by Chao Fen Sun