Also in Linguistics what is a subject?
closed as general reference by Richard Rodriguez, Mehper C. Palavuzlar, Matt Эллен, JSBձոգչ, Daniel δ Dec 7 '11 at 18:06
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In the English language we have only vestiges of case, like the nominative and the accusative that you mention. You can find them in pronouns:
Nominative: I, you, he, she, it, we, you, they. Accusative: me, you, him, her, it, us, you, them.
The nominative case is used for the subject of the verb, i.e. the word which denotes who/what does what the verb says. The accusative case marks the object of the verb, i.e. the word which receives the action of the verb (when there is such a receiver):
He offended me. He: nominative, subject of the verb. Me: accusative, object of the verb.
In many languages, nominative is the case that typically marks subjects while accusative is the case that typically marks objects. In modern English, these cases are only marked in the personal pronouns. For example, I is marked for nominative case and me is marked for accusative. Other terms are also used for these cases.
There are instances where it is grammatical for pronouns marked for other cases take over these functions. Genitives like my, for instance, can function as the subject of a participial clause (e.g., He hated my getting the position over him, where my is the subject of getting the position).
According the A Student's Introduction to English Grammar, a subject is
In addition, in present tense clauses, there will typically be number agreement between the verb and the subject.