As a collective noun, it's both singular and plural.
The word team is singular; the plural form is teams.
These is plural, this is singular
Lance is singular. Lances is plural.
The word 'Phenomenon' is singular. The plural form is 'Phenomena'.
The word metastasis is singular, metastases is plural.
The word "ground" can be both singular and plural. Singular: "The ground is wet." Plural: "The grounds of the park are well-maintained."
Louse is singular. The plural form is lice.
No, the word "list" is singular. The plural form of "list" is "lists."
It's singular. The plural is cafeterias.
Verbs cannot be singular or plural. Has is after singular nouns.
Tool is singular. Tools is plural.
Caveman is singular. Cavemen is plural.