one and a half做主语谓语动词用单数还是复数

问题描述:

one and a half做主语谓语动词用单数还是复数
在牛津高阶英语第六版中788页one and a half做主语谓语单复数都行,但是有些说用单数视为整体,您怎么看?

one and a half +名词复数
One and a half years have passed since I saw him.
我已经一年半没见到他了.(谓语动词复数形式)