Both singular and plural.
The word snow is both singular and plural like sheep.
neither, actually no dirt exist other than political
No, expedition is singular. The plural form is expeditions.
The noun 'dirt' is an uncountable noun; a word for a substance, such as mud or dust; loose soil or earth.
The plural form of the word "rock" is "rocks."
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.
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.
Singular Plural is caterpillars