主语主语是句子的主体，是句子所要说明的人或物，表示句子描述的是“谁”或“什么”。主语通常由名词、代词、数词、动词不定式、动名词或主语从句等担任，其位置在陈述句基本结构的前部。如：Professor Wang is a wellknown scholar.王教授是一位著名的学者。（名词）I read newspaper every day.我每天读报。（代词）Three plus six is nine.三加六得九。（数词）To become a professor has been his ambition.当教授一直是他的抱负。（不定式）Smoking is harmful to health.吸烟对健康有害。（动名词）What we shall do next is not yet decided.下一步我们做什么还未定下来。（主语从句）The aged are well taken care of in the village.这个村里的老年人都得到了很好的照顾。（名词化的形容词）谓语谓语说明主语的动作或状态的部分。
