Of course, I just pulled this off the top of my head.......
Subjects and Objects
The question of the subject or object of the sentence or clause depends upon the verb. We need to know if the pronoun in question is doing the action, or is being done to. It is not a question of which comes first in the sentence or clause. It's a question of which word is "using" the verb.
The subject of the sentence or clause is the star. The subject is the one who is active, who does things to other people, places, or things.
The direct object of the sentence or clause is the focus of the verb. The direct object is the one who is passive, who receives the things the subject is doing with the verb.
So, if I tell a joke, I am the subject of the sentence, because I'm doing the telling, and the joke is the object of the sentence, because it's being told. I am active, and the joke is passive.
The subjects in the following sentences are in red. The direct objects are in green.
An elephant eats grass.
My mother also majored in English.
Compound Subjects
Sometimes a clause has more than one person or thing doing the verb. This means the sentence has a compound subject. The good news is that nothing changes. You just put all the subjects in the subjective case and continue on.
My mother and sister both read books voraciously.
She, Bob and I went out for pizza and a movie.
Indirect Objects
Sometimes, especially when you're writing about acts of giving or speaking, the verb and the direct object require futher elaboration to complete our understanding of the action. The sentence will then use an indirect object, usually accompanied by a preposition like "to" or "by."
The subjects in the following sentences are in red. The direct objects are in green. The indirect objects are in purple.
Billy gave the cola to Diane.
The quarterback passed the ball to the receiver.
Note that the terms "direct" and "indirect" actually make sense here. The quarterback is not doing something directly to the receiver. He's throwing the ball, and the ball goes to the receiver. The connection between the quarterback and the receiver is indirect. The same is true of Billy, the cola, and Diane.
There's one thing to remember.
All forms of the verb "to be" (is, are, was, were, have been, will be, etc.) do not create an objective case.
This too makes sense if you think about it. The verb "to be" doesn't actually have action so much as simple existence. If I say "The apple is red," the apple isn't doing anything to the color red, it simply is red. And if I say, "Red is the color of the apple," once again the color red isn't doing anything to the apple. Red simply exists as the color of the apple.
In the sentence:
They are Brazilians.
Both "They" and "Brazilians" are subjects.
And if I say:
He is a very tall man.
There is no object in the sentence. "He" and "man" are both subjects.