"Earth" is a thing, and "things" are nouns.
"Earth", then, is a noun.
many species are in danger of vanishing from (the face of ) the earth
The word earth is a noun. The planet Earth is a proper noun.
adverb
what part of speech is work
i want to know what part of speech is camping
what part of speech is beneath
The word earth is a noun. The planet Earth is a proper noun.
Extraterrestrial is an adjective, meaning not of this Earth.
"Stratosphere" is a noun because it is a thing on Earth.
"to water the earth" is a verbal phrase- more precisely an infinitive phrase. It could be expressed as "to irrigate"
The part of speech for "answer" is a noun.
part of speech
The part of speech for this particular word is a noun.
The word geothermal is an adjective. It means pertaining to heat energy extracted from the earth's interior.
adverb
what part of speech is work
what part of speech is beneath
The part of speech for "explicit" is an adjective.