I can echo you can echo he can echo we can echo you can echo they can echo
V-ing form
I can be echoing you can be echoing he can be echoing we can be echoing you can be echoing they can be echoing
Perfect
I can have echoed you can have echoed he can have echoed we can have echoed you can have echoed they can have echoed
V-ing perfect
I can have been echoing you can have been echoing he can have been echoing we can have been echoing you can have been echoing they can have been echoing
Negation
Simple form
I cannot echo you cannot echo he cannot echo we cannot echo you cannot echo they cannot echo
V-ing form
I cannot be echoing you cannot be echoing he cannot be echoing we cannot be echoing you cannot be echoing they cannot be echoing
Perfect
I cannot have echoed you cannot have echoed he cannot have echoed we cannot have echoed you cannot have echoed they cannot have echoed
V-ing perfect
I cannot have been echoing you cannot have been echoing he cannot have been echoing we cannot have been echoing you cannot have been echoing they cannot have been echoing
Interrogative form
Simple form
can I echo? can you echo? can he echo? can we echo? can you echo? can they echo?
V-ing form
can I be echoing? can you be echoing? can he be echoing? can we be echoing? can you be echoing? can they be echoing?
Perfect
can I have echoed? can you have echoed? can he have echoed? can we have echoed? can you have echoed? can they have echoed?
V-ing perfect
can I have been echoing? can you have been echoing? can he have been echoing? can we have been echoing? can you have been echoing? can they have been echoing?
Interro-negative form
Simple form
can I not echo? can you not echo? can he not echo? can we not echo? can you not echo? can they not echo?
V-ing form
can I not be echoing? can you not be echoing? can he not be echoing? can we not be echoing? can you not be echoing? can they not be echoing?
Perfect
can I not have echoed? can you not have echoed? can he not have echoed? can we not have echoed? can you not have echoed? can they not have echoed?
V-ing perfect
can I not have been echoing? can you not have been echoing? can he not have been echoing? can we not have been echoing? can you not have been echoing? can they not have been echoing?