The plural of plant is plants.
The word lilies is the plural form of the noun lily, a word for a type of plant.
I think you are going for cactus, any of several kinds of spiky desert plant. You can use either cacti or cactuses as the plural form.
No, it is singular. The plural of plant manager is plant managers
The plural form of the noun fungus is fungi.The plural possessive form is fungi's.
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."
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.
"Groceries" is the plural form of "grocery."