1. sometime 和 sometimes 都不可以做谓语,因为它们都是时间副词,只能所状语,前者表示“某时”,后者表示“有时”.例如:
1)He went to see his uncle sometimes when he was in Beijing. 他在北京的时候有时去看他的叔叔.
2)I'll come to see you this afternoon. 我下周某个时候来看你.
2. some time 确实是两个词,因为分开来写的,意思是 “一些时间”,例如:
I stayed in his office for some time. 我在他的办公室里待了一些时候.