Explain the purpose of the apostrophe in each word, and explain what the apostrophe is probably replacing. If there is more than one possibility, try to get all possibilities and explain each.

 
1. It's

2. Sue's
 
3. D'Giorno
 
4. We'll
 
5. '70s
 
6. Bill's
 
7. 'til
 
8. They're
 
9. Aren't
 
10. O'Reilly
 

except for 2 and 6 (which indicate possession), the apostrophes indicate a missing letter.

Even 2 and 6 can mean that, if you meant to say
Sue's going to sue me.
short for "Sue is going to sue me."

oobleck is right.

Plus, #5 involves missing numerals -- '70s means 1970s.

1. The apostrophe in "It's" is replacing the letter "i" and the verb "is." It is a contraction of "it is." In this case, the apostrophe is used to combine the pronoun "it" with the verb "is" to form a contraction.

2. The apostrophe in "Sue's" is replacing the letter "i" and indicates possession. It is a contraction of "Sue" and "is." In this case, the apostrophe is used to show that something belongs to or is associated with Sue.

3. The apostrophe in "D'Giorno" is replacing the letter "e" and is part of the surname. It is commonly seen in Italian names and is used to indicate the omission of a letter or letters. In this case, the apostrophe is replacing the missing letter "e" between "D" and "Giorno."

4. The apostrophe in "We'll" is replacing the letter "wi" and the verb "will." It is a contraction of "we" and "will." In this case, the apostrophe is used to combine the pronoun "we" with the verb "will" to form a contraction.

5. The apostrophe in "'70s" is replacing the numbers "19" and indicates the omission of the century. It is used to form contractions for decades. In this case, the apostrophe is replacing the missing numbers "19" in "1970s."

6. The apostrophe in "Bill's" is replacing the letter "wi" and indicates possession. It is a contraction of "Bill" and "is." In this case, the apostrophe is used to show that something belongs to or is associated with Bill.

7. The apostrophe in "'til" is replacing the letter "un" and the word "until." It is a contraction of "until." In this case, the apostrophe is used to combine the letters "un" with the word "til" to form a contraction.

8. The apostrophe in "They're" is replacing the letter "a" and the verb "are." It is a contraction of "they" and "are." In this case, the apostrophe is used to combine the pronoun "they" with the verb "are" to form a contraction.

9. The apostrophe in "Aren't" is replacing the letter "a" and the verb "are." It is a contraction of "are" and "not." In this case, the apostrophe is used to indicate the omission of the letter "o" in "are" to form a contraction.

10. The apostrophe in "O'Reilly" is replacing the letters "O" and "Of." It is commonly seen in Irish surnames and is used to indicate the omission of letters. In this case, the apostrophe is replacing the missing letters "O" and "f" in the surname "O'Reilly."