Se podría creer
que se forma el past perfect en
frases con un verbo modal
de la misma manera en la que se forma el present perfect con un verbo modal pero
utilizando el simple past
del verbo modal en vez
del simple present. Pero
no es así. Como ya lo hemos mencionado varias veces,
el simple past de un verbo
modal sirve para formar el condicional
y por lo tanto no se puede utilizar para formar el past
perfect. El simple past de un verbo modal es un condicional
II.
He could do it = Podría hacerlo.
Formación del past perfect
con verbos modales utilizando el simple past
= condicional II
verbo modal
+ have
+ participio
could
have
gone
podría haberse ido
might
have
done
podría haber hecho
should
have
written
debería haber escrito
needed to
have
read
debería haber leído
Para evitar cualquier ambigüedad hay que construir
con una perífrasis.
Ejemplos
verbo auxiliar
perífrasis
perífrasis en
el past perfect
can
=>
to be able to
had been able to
may
=>
to be
allowed to
had
been allowed to
must
=>
to have to
to be obliged to
to be forced to
to be compelled to
had had to
had been obliged to
had been forced to
had been compelled to
shall =>
to be
to
had
been to
will =>
to want to
to wish
had wanted
to
had wished to
Para ver más claro.
Present perfect: I have seen him. con un
verbo modal: I can
have seen him
Past perfect: I had seen him.
con un verbo
modal: I could have
seen him.
=>Es un condicional: Habría
podido verlo.
Past perfect: I had seen him.
I had been able to see him.
=> Había
podido verlo.