Perfect continuous infinitive

El "perfect continuous infinitive" se utiliza para expresar una acción continuada que ya ha concluido en el momento actual, detrás de un verbo que debe ir seguido de infinitivo. Formación del "perfect continuous infinitive":
to have been + present participle

Como ocurre con el "present infinitive", hay construcciones que requieren el uso del "perfect continuous infinitive" sin la partícula "to". Esto ocurre detrás de la mayoría de los auxiliares y modales, así como en otras instancias en que se emplean infinitivos sin "to".

Ejemplos
  • The woman seemed to have been crying.
  • He pretended to have been painting all day.
  • I would have preferred to have been sleeping all afternoon.
  • You must have been waiting for hours!
  • They might have been talking before you came in.
  • You should have been studying for your test.