In Spanish, the perfect infinitive (infinitivo compuesto) is simply the word haber followed by the past participle of a verb. It is the equivalent of the English infinitive "to have" followed by a past participle and is used in basically the same way. You can see the similarities of the two languages' perfect infinitives in these examples:
- Haber llegado tan lejos fue memorable para nosotras. To have arrived so far away was memorable for us.
- Fue un error haber hecho todo. It was a mistake to have done everything.
- Espero haber sido de ayuda. I hope to have been of help.
- Quería haber tenido más tiempo. I wanted to have had more time.
- Mas vale haber amado y perdido que no haber amado nunca. 'Tis better to have loved and lost than to never have loved at all.
- El 34% de los niños aseguran haber visto a Papá Noel. Thirty-four percent of children claim to have seen Santa Claus.
- íQué afortunada soy por haber conocido el verdadero amor! How fortunate am I for having known true love!
- Su pecado es haber nacido en Cuba. His sin is having been born in Cuba.
- Tengo la sensación de haber hecho todo lo posible. Have have the feeling of having done everything possible.
- Fujimori niega haber conocido existencia del grupo Colina. Fujimori denies having known the existence of the group Colina.
- Imaginaba haber encontrado el dinero. He imagined having found the money.
- Gracias por haber confiado en nosotros. Thank you for trusting in us.
- Gracias por haber llegado a mi vida. Thank you for coming into my life.
- ¡Cómo desearía no haberte conocido! How I wish I had never met you!
- Recuerdo haberle comprado dos cajas de cereal. I remember buying two boxes of cereal for him.

