El present perfect continuous ya tiene un verbo auxiliar,
to have, y este verbo
auxiliar se utiliza para la negación.
Ejemplos
He
has been writing
a letter
He
has not (haven't) been writing a letter
She
has been reading
an article
She
has not (haven't)
been reading an article
We have
been watching
TV
We have
not (haven't) been watching TV
They
have been building
a house
They
have not (haven't)
been building a house
You
have been planning
a trip
You have
not (haven't) been planning a trip
En el caso de que haya un verbo modal, es este verbo modal
que hay que negar. No discutimos sobre la relevancia de este tipo de construcciones. Se entiende sin problemas que construcciones de este tipo son un poco "exóticas".
Ejemplos
Hecould not
have been doing his homework
No podía
estar haciendo sus tareas
She
might not have been
reading an article in that moment
A lo mejor
no estaba leyendo un artículo en ese
momento
They
did not need to have
been watching TV to get the news
No hacía
falta que estuviesen mirando la tele para
estar enterados.
We
should not have
been partying all night instead of
studying
En vez de ir a la fiesta
habría sido mejor estudiar
