一共有哪些形式可做主语

名词: the fish is fresh.
代词: this is a pen
数词: two will be enough
动名词: sleeping is beneficial to health
不定式:to chat with foreigner is a challange
词组或复合结构:all work and no play make jack a bull boy
从句:that they failed in their attempt is entirely understandable.
名词性的其他词类:
'a' is an article
the poor can not afford a apartment

以下偶见于口语,不能说错,但最好少用:
副词:slowly is exactly how he speaks
介词短语:out on the lake will be all right

名词 人称代词 动名词 不定式 有what引导的名词性短语如what you said 等等
最好找本语法书 ，还有详细的解释和例句。

名词性物主代词，一般名词，人名物名