Subject and object forms
FIRST PERSON | SECOND PERSON | THIRD PERSON | ||
SINGULAR | Subject | I | you | he/she/it |
Object | me | you | him/her/it | |
PLURAL | Subject | we | you | they |
Object | us | you | them |
We use the subject form (I, you, he, she, it, we, they) when the pronoun is the subject and there is a verb.
I don't think so. Maybe she's just forgotten.
We use the object form (me, you, him, her, us, them) when the pronoun is the object of a verb or preposition.
I haven't seen her today. I hope they haven't gone without me.
The pronoun on its own or after be usually has the object form.
Who spilt coffee all over the table? ~ Me./Sorry, it was me.
Compare this answer.
Who spilt coffee all over the table? ~ I did.