The word yesterday is an adverb.
An adverb of time.
It's an adverb.
The part of speech for the word diplomacy is a noun.
The part of speech for the word civilian is English grammar.
The word speech is a noun.
The part of speech for oscillate is verb.
Yesterday is a noun in that sentence.
Yesterday he paddled his canoe out into the lake and camped on an island overnight.
"Yesterday" is an adverb modifying the noun "afternoon".
Yesterday is an adverb in that sentence.
She gave a terrific speech yesterday.
Walked is a verb.
I think yesterday is a noun, because it is definitley not a verb or adjective. It is not an action and it does not describe anything.
It's an adverb.
In the sentence "yesterday the leaves hung on the tree," "yesterday" is functioning as an adverb modifying the verb "hung."
The part of speech for this particular word is a noun.
The part of speech that the word my is used as is an adjective.
The word "unbearable" is an adjective. It describes something that is not able to be endured or tolerated.