Which verb form is used to indicate the perfect progressive tense?

A. verb + - ed

B. be + verb + - ing

C. have + been + verb + - ing

D. have + verb + - ed

C) have + been + verb + - ing.

The correct answer is C. Have + been + verb + - ing. Al perfect forms are made by adding have and been but are somewhat rare in US english when not used in conditional sentences. Progressive indicates that a present participle (verb with an - ing ending), instead of a regular participle which would be the - ed verb.