that means you don't need to water the garden

问题描述:

that means you don't need to water the garden
这里的mean+S是因为什么 mean是动词吗
还有don't need to 可以换成 needn't

这里的mean作动词“意味着”讲,前面的主语“that”被看作第三人称单数,因此动词后面要加s
don't need to 可以换成 needn't to