Stems
Stems is a noun (plural form of stem) and a verb (third person singular conjugation of stem).
Daisies is the plural form of daisy. The plural possessive is daisies'.
Xylem (the vascular tissue in plants which conducts water and dissolved nutrients upwards from the root and also helps to form the woody element in the stem) is a mass noun, the plural form of which is xylems.Phloem (the vascular tissue in plants which conducts sugars and other metabolic products downwards from the leaves) is a mass noun, the plural form of which is phloems.
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."
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."
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.