plural of perfect passive participle

(grammar) A tense that expresses an unbroken action continuing up to a certain time in the past. In English it is formed by using had been with a present participle.

past perfect continuous

(grammar) present perfect continuous

Future perfect continuous.

(grammar) A tense used to express an ongoing action completed after some time in the future. In English it is formed by use of will have been (or shall have been) and a present participle.

(grammar) A tense that expresses an unbroken action continuing at the present time, started in the past. In English it is formed by using have been with a present participle.

Insistence on perfection often precludes the opportunity for something worthwhile. / Insistence on perfection precludes gradual improvement through compromises.

plural of present perfect progressive

A scenario that can be found in market dominated by a monopoly firm which is able to charge each consumer different prices based on certain characteristics.