Ma (1977) stated that guò 過 only occurs in repeatable events, for example,
*哥倫布發現過美洲大陸。
*Gēlúnbù fāxiàn guò měizhōu-dàlù
Columbus discover GUO American continent
‘Columbus discovered the American continent.’
However, Liu (2015) refuted that guò 過 can be used in unrepeatable events,
For example,
哥倫布發現過美洲大陸和太平洋上的小島。
Gēlúnbù fāxiàn guò měizhōu-dàlù hé tàipíngyáng-shàng-de xiǎodǎo
Columbus discover GUO Am.-continent and Pacific.ocean-on DE small.islands
‘C. has discovered Am. Continent and some small islands on the Pacific Ocean.’
