I could attenuate you could attenuate he could attenuate we could attenuate you could attenuate they could attenuate
V-ing form
I could be attenuating you could be attenuating he could be attenuating we could be attenuating you could be attenuating they could be attenuating
Perfect
I could have attenuated you could have attenuated he could have attenuated we could have attenuated you could have attenuated they could have attenuated
V-ing perfect
I could have been attenuating you could have been attenuating he could have been attenuating we could have been attenuating you could have been attenuating they could have been attenuating
Negation
Simple form
I could not attenuate you could not attenuate he could not attenuate we could not attenuate you could not attenuate they could not attenuate
V-ing form
I could not be attenuating you could not be attenuating he could not be attenuating we could not be attenuating you could not be attenuating they could not be attenuating
Perfect
I could not have attenuated you could not have attenuated he could not have attenuated we could not have attenuated you could not have attenuated they could not have attenuated
V-ing perfect
I could not have been attenuating you could not have been attenuating he could not have been attenuating we could not have been attenuating you could not have been attenuating they could not have been attenuating
Interrogative form
Simple form
could I attenuate? could you attenuate? could he attenuate? could we attenuate? could you attenuate? could they attenuate?
V-ing form
could I be attenuating? could you be attenuating? could he be attenuating? could we be attenuating? could you be attenuating? could they be attenuating?
Perfect
could I have attenuated? could you have attenuated? could he have attenuated? could we have attenuated? could you have attenuated? could they have attenuated?
V-ing perfect
could I have been attenuating? could you have been attenuating? could he have been attenuating? could we have been attenuating? could you have been attenuating? could they have been attenuating?
Interro-negative form
Simple form
could I not attenuate? could you not attenuate? could he not attenuate? could we not attenuate? could you not attenuate? could they not attenuate?
V-ing form
could I not be attenuating? could you not be attenuating? could he not be attenuating? could we not be attenuating? could you not be attenuating? could they not be attenuating?
Perfect
could I not have attenuated? could you not have attenuated? could he not have attenuated? could we not have attenuated? could you not have attenuated? could they not have attenuated?
V-ing perfect
could I not have been attenuating? could you not have been attenuating? could he not have been attenuating? could we not have been attenuating? could you not have been attenuating? could they not have been attenuating?