The word followed is a verb. It is the past tense of follow.
Under the conditions given, "to" is a preposition.
Ethics code is a noun. It is rules of code which must be followed in order to be ethically correct.
active verbs followed by active nouns
Ethics code is a noun. It is rules of code which must be followed in order to be ethically correct.
"were serving" is a verb phrase consisting of the past tense of the verb "to be" (were) followed by the present participle of the verb "to serve" (serving).
The word 'throughout' is a preposition when followed by a noun:Prices continued to rise throughout the decade.The word 'throughout' is an adverb when it's not followed by a noun:It was a difficult time but my family supported me throughout.
Following is a verb. It describes an action.
part of speech
The part of speech for this particular word is a noun.
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath