past perfect tense vs past perfect

past perfect tense and past perfect both are nouns.

Word	Noun	Adjective	Verb	Adverb
past perfect tense	Yes	No	No	No
past perfect	Yes	No	No	No

As nouns, past perfect tense and past perfect are synonyms defined as:

past perfect tense and past perfect: a perfective tense used to express action completed in the past

Other synonyms of past perfect tense include pluperfect, pluperfect tense.

past perfect tense (noun)	past perfect (noun)
a perfective tense used to express action completed in the past	a perfective tense used to express action completed in the past