Hi sir,
I don't know when to use parentheses or brackets.
Can someone tell me the difference between parentheses and brackets.
And give me some sentences.
Thank you very much.

Parentheses enclose words, phrases, clauses or sentences that are placed within the sentence mainly for explanation or commentary. They are constructions unto themselves, separate from the rest of the sentence:

She told him that she would be a little late (she was never on time for anything) and to start dinner without her.

Parentheses also enclose numbers, letters and symbols in the same fashion when they are used as appositives in a sentence:

The algebraic expression (f(x)=a(x-1)(x-1)[x-(-4+i)][x-(-4-i)]) is beyond me. -numbers

I do not understand why I received a failing grade -F- on my test.-letter

You forgot the "at" -@- in your email address.-symbols

Parentheses also enclose items in a sentence:

Today, I will (1) drive to the mall, (2) buy some Christmas presents, and (3) spend a few hours looking for my car in the parking lot.

Brackets are used to enclose parenthetical material within parentheses:

I (leader of the free world [most powerful man on earth]) will no longer stand for these trade agreements.

Brackets also enclose information that an editor includes or inserts into a quote:

"It wasn't very civil of you to sit down without being invited [to the tea party]," said the March Hare.

Note: in the sentences with -F- and -@- replace each hyphen with a parenthetical mark. When I tried using the parentheses with these symbols it posted a rose and a cow (dog or cat, maybe?).