It describes things, so it's an adjective.
adverb
what part of speech is work
i want to know what part of speech is camping
what part of speech is beneath
what part of speech is eleven
I would argue by definition a Navy is amphibious but it is not the main part of the Navy that is. One of the prime missions of the Marine Corps is Amphibious operations and since the Marine Corps is part of the Navy the Navy as a whole is amphibious.
There were no amphibious tanks used in WW1. Tanks were only used in the late World War, and they were not technically advanced enough to be amphibious. For "the late" substitute "the latter part of", and add "1" after "War".
part of speech
The part of speech for this particular word is a noun.
what part of speech is beneath
what part of speech is work
adverb
Sashay is a verb. It means to walk in an exaggerated, showy manner, often with hip swaying.
"Did not" or "didn't" is a contraction of the auxiliary verb "did" and the adverb "not," forming a negative past tense construction in English.
A whale. Amphibious means "capable of functioning on land or in water". Whales are not amphibious. Frogs are amphibious.
The word speech is a noun.
Adjective