Verbos Modales en Pasado
(Poder)

Can + Have + v. p. pas.

May + Have + V. p. pas.

Might + Have + V. p. pas.

Could + Have + V. p. pas.

Posibilidad

Reevaluations should be thorough, since exposure
to viruses can have taken place.

Can't + Have + v. p. pas.

Deducción

The two systems can't have had the same virus
because the damages were different.

Critica Por una accion pasada

Posibilidad

Verbos Modales en Pasado (Deber)

Must + Have + V. p.pas.

Should + Have + V.p.pas

Ought to + Have + V. p. pas.

Oblicacióon

Deducción

Crítica/arrepentimiento
por una acción pasada

Acciones que se esperaba que ocurrieran, pero no ocurrieron

Crítica/arrepentimiento
por una acción pasada

Anhelo por algo que no ocurrio

Posibilidad

Posibilidad

The antivirus, however, may have reacted more to
the virus infections than to other apps.

If we had utilized a simple routine method, the outcome might have been adverse to our expectations

There were other devices with much less serious
damages that could have had the same virus.

You could have told me you were buying a new
device.

The engineer must have changed the device to
protect the system.

Engineers must have bought new software a year
before the new hardware approval.

The new engineer should have purchased a new device even though the conclusive diagnoses had not yet been made.

The notebook should have started by now

The client ought to have waited longer for the PC to
be ready

The results ought to have arrived by now