Cow is a noun.
Cow's is a singular possessive noun--cow's milk.Cows is a plural noun.
THEIR dog
Why did the mommy cow win an award for her speech on how much she loved her calf? She won the award because the audience thought her speech was very moooooo-ving.
Just part of it
the power of speech
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
what part of speech is beneath
adverb
The part of speech for "explicit" is an adjective.
The part of speech for "lecturer" is a noun.