Yes, for example:
deer
It can be either. The plural of salmon may be either salmon or salmons.
The noun 'shrimp' is singular or plural.The plural noun is either 'shrimp' or 'shrimps', both are accepted.
"corn" is a common noun that can be either singular or plural
No. Either genitive singular or nominative plural.
The noun 'mice' is the plural form of the singular noun 'mouse'.
The singular noun is "louse" and the plural noun is "lice."
Headquarters is both singular and plural.
noun that are plural in form but singular in meaning
The noun children is the plural form of the singular noun child.
The noun 'circus' is a singular noun.The plural noun is 'circuses'.
The noun juggler is a singular noun. The plural noun is jugglers.
The singular noun is Tuesday.The plural noun is Tuesdays.