the boy lay on the grass,staring at the sky

问题描述:

the boy lay on the grass,staring at the sky
为什么lay不用现在分词?

lying(lie的现在分词),不能单独作为谓语的.
The boy lay on the grass,staring at the sky=The boy lay on the grass and stared at the sky
这句子中,staring at the sky为现在分词短语,作状语,表示谓语动词lay(lie的过去式)发生时的伴随状况.为什么lying不能单独作谓语?动词不定式,动词现在分词,动名词,动词过去分词为动词的非谓语动词,均不可单独作谓语。语法规则