Bridges is the plural form of bridge.
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.
There is no plural form for the word, countries. This word itself is a plural.
The plural of "she" is "they", so the plural of "she had" is "they had".
There is no plural form of pupae. Pupae is the plural form of pupa.
'They are in the Caribbean.' is a complete sentence. There is no missing plural noun. The pronoun 'they' replaces the names of those who are in the Caribbean. With just that sentence we don't know what 'they' represents, the Smiths, the honeymooners, the contest winners. More than likely that plural pronoun was in a preceding sentence.
The plural form of him, her, or it is them. (objective pronouns)
Bridges is the plural form of bridge.
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.
There is no plural form for the word, countries. This word itself is a plural.
"Groceries" is the plural form of "grocery."
The plural form of "meter" is "meters."
The plural form of the demonstrative pronoun 'that' is those.
The plural form for the noun sergeant is sergeants; the plural possessive form is sergeants'.
It has no plural form.
The plural form of rung is rungs.
The plural form of parenthesis is parentheses.