Guards
The plural form for the noun guard is guards.
Guard-houses.
Singular: guardPlural: guards
The plural of guard is guards. As in "the dog closely guards the cookie she just stole".
doctors' guards' jockeys' milkmen's umpires'
house
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 "was" is "were."
The plural form of "I" is "we."
The plural form of "is" is "are."