Nazis is the plural form of Nazi.
Audis is the plural form Audi's is the possessive form Audis' is the plural possessive form The plural of Nazi is Nazis. The apostrophe is only used for possessive or to indicate missing letters, as in "it is" -> "it's", or "can not" -> "can't" Wiktionary.org/ does not have one noun that I could see that had a plural created by adding "'s", with the exception of "diva's" which I think can be contested. The same goes for abbreviations like CD and DVD -> CDs and DVDs. NO APOSTROPHE!
There is no plural form. Do and Do not are verbs
The plural form of him, her, or it is them. (objective pronouns)
Bridges is the plural form of bridge.
The plural form of "is" is "are."
The plural form of "I" is "we."
The plural form of "was" is "were."
"Groceries" is the plural form of "grocery."
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.
The plural form of mouth is mouths. The plural form of month is months. The Mounth is a range of hills in Scotland and does not have a plural form.
The plural form of the demonstrative pronoun 'that' is those.
The plural form is metres.