The word swept is the past participle, past tense of the verb to sweep (He swept the floor.), and an adjective, a word that describes a noun (The plane had a swept wing.). There is no plural form for a verb or an adjective. Nouns and pronouns have plural forms.
The plural form of "do" is "do" and the plural form of "don't" is "don't." These words do not change in the plural form when used in a sentence.
The plural form of him, her, or it is them. (objective pronouns)
Bridges is the plural form of bridge.
The plural form of "was" is "were."
The plural form of "I" is "we."
The plural form of "is" is "are."
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.
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.
"Groceries" is the plural form of "grocery."
The plural form of "meter" is "meters."
The plural form of the demonstrative pronoun 'that' is those.