Yes, reindeer is a countable noun; however, like the noun deer, the singular and the plural are spelled the same: one reindeer, eight reindeer.
A uncountable noun (or mass noun) is noun for a substance or concept that is indivisible into countable units, words like water and knowledge.
Singular Plural is caterpillars
The word crisis is singular. The plural form of crisis is crises.
Steroids is plural. The singular form of the word is steroid.
The word address is singular; the plural form is addresses.
Association is singular. Associations is plural.
The singular possessive for reindeer is reindeer's.
The noun reindeer is both the singular and the plural; the singular and the plural possessive form is reindeer's.
The plural possessive form of "reindeer" is "reindeers'." In this case, the plural form of "reindeer" is "reindeer," and to show possession, you add an apostrophe after the "s" in the plural form. This indicates that something belongs to multiple reindeer.
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'.
das Renntier (singular) die Renntiere (plural)
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."