Theory:

Punctuation marks are symbols used to organise and structure sentences. The term “punctuation” is derived from the Latin word “punctum”. They are used for understanding a sentence correctly. Punctuation is used to bring clarity and meaning in writing.
The most common punctuation marks in English are capital letters, full stops, question marks, commas, brackets, exclamation marks and quotation marks.
Let's see about some of the punctuation marks and its examples:
Capital Letter: A capital letter (A,B,C) is used while starting a sentence and used for proper nouns.
Example:
1. The book is written by Albert Einstein.
2. Kala, Raju, Rekha
Full stop: A full stop (.) is used at the end of a sentence. While using the full stop in a sentence, it denotes that the sentences had given complete meaning. The full stop is otherwise called a period.
Example:
1. Sheela went to the park yesterday.
2. Ramesh likes to eat chocolates.
Question mark: A question mark (?) is a punctuation mark that indicates an interrogative clause or phrase in many languages. The question can be a short word or a whole sentence. When we use a question mark, we do not use a full stop.
Example:
1. What is your name?
2. How old are you?
Exclamation mark: An exclamation mark (!) is used to express a strong emotion or feeling.
Example:
1. We won!
2. It’s a boy!
3. I’m going to miss this place!
Comma: A comma (,) is used to separate a list of similar words or phrases.
Example:
1. There are apples, oranges, and bananas in the basket.
2.Wordsworth, the famous English poet, was a lover of nature
Quotation mark: Quotation marks (" ") are used to mark the beginning and end of a title or quoted passage. They are also used in direct speech.
Example:
1. The king shouted, Let the games begin!
2. My favourite novel of all time is Anne Rice’s Interview with the Vampire.
Bracket: Brackets ( ) are used in a sentence to give some additional information.
Example:
1. The anklets (which had been in my family for years) was stolen.
Hyphen: A hyphen is a short line ( - ) used to connect the parts of a compound word or to connect split words such as numbers (twenty-nine) and job titles (vice-president). Also it used to join words to indicate that they have a combined meaning.
Example:
1. book-keeper
2. ice-cream
Some of the punctuation marks used in the "A Truly Beautiful Mind" are:
 
S.No
Sentence
Punctuation marks
1
His playmates called him Brother Boring.”Quotation marks (" ") and Period (.) 
2
The youngster played by himself much of the time. Period or Full stop (.)
3
He also felt a special interest in a fellow student, Mileva Maric, whom he found to be a “clever
creature.”
Comma (,) Quotation marks (" ") and Period (.) and Capital letter (M,M)
4
At the age of two-and-a-half, Einstein still wasn’t talking.Hyphen ( - ) Period (.) and Comma (,)
5
“The soup is too hot.”Quotation marks (" ") and Period (.) 
6
German city of Ulm.
Capital Letter (G,U) and Period (.) 
7
“Fine, but where are her wheels?”Question mark (?) Quotation marks (" ") and Comma (,)