Yes, an apostrophe is a punctuation mark used to indicate either possession or contraction in writing.
Yes
The apostrophe is generally used to show possession or a contraction. Example 1: "Melissa broke her brother'sskateboard." In this sentence we can see that the apostrophe is used to tell us that the skateboard Melissa broke belongs to her brother. Hence, the apostrophe is used to show possession. Example 2: "Melissa thinks that her brother's a jerk." In this sentence we can see that the apostrophe is used to contract or shorten "brother is." Hence, the apostrophe is used to show a contraction. Other, more common contractions, such as "isn't" (is not) and "don't" (do not) are formed similarly. The best way to decide the proper use of an apostrophe is to know what it is you are writing about. Ask yourself, "Am I writing about a thing that belongs to someone, or am I trying to shorten two words into one?"
"Each of the boys' are writing a different story."The first mistake is to say "Each are." If you're talking about each one, the correct verb is "Each is writing."The second is to try to use an apostrophe to make a plural. The apostrophe indicates possession, not plural. The correct sentence would be "Each of the boys is writing a different story."
If the last name is plural or singular, ends in s or any other letter, it will always end in apostrophe s if it is signifying possession. Example: The Jones's house The Johnson's place
If you are just writing about peanuts, it does not need an apostrophe.If the peanuts have a belonging or possession, then yes, it needs an apostrophe.The peanuts were salty.The peanuts' saltiness added flavor.
No. Most style guides suggest that the apostrophe is not needed to indicate the plural.Other than these erstwhile exceptions, the apostrophe is an indicator of possession, not plurals. Unless there is a need to avoid confusion, you can write the plural of 7 as 7s.
Only if you're writing about their car, house, or something else they possess. Otherwise, if your signing a card or something, no apostrophe is needed. Now, "The Alvarezs" looks odd to me. It might be better if written "The Alvarez family".
No.
You can use an apostrophe when contracting "is" with a person's last name to indicate possession or a contraction of "is." For example, "Sarah's here" (indicating possession) or "Johnson's coming over" (contracting "is").
descriptive writing
This should only happen if they are referring to something belong to the banana.