I could fatigue you could fatigue she could fatigue we could fatigue you could fatigue they could fatigue
V-ing form
I could be fatiguing you could be fatiguing she could be fatiguing we could be fatiguing you could be fatiguing they could be fatiguing
Perfect
I could have fatigued you could have fatigued she could have fatigued we could have fatigued you could have fatigued they could have fatigued
V-ing perfect
I could have been fatiguing you could have been fatiguing she could have been fatiguing we could have been fatiguing you could have been fatiguing they could have been fatiguing
Negation
Simple form
I could not fatigue you could not fatigue she could not fatigue we could not fatigue you could not fatigue they could not fatigue
V-ing form
I could not be fatiguing you could not be fatiguing she could not be fatiguing we could not be fatiguing you could not be fatiguing they could not be fatiguing
Perfect
I could not have fatigued you could not have fatigued she could not have fatigued we could not have fatigued you could not have fatigued they could not have fatigued
V-ing perfect
I could not have been fatiguing you could not have been fatiguing she could not have been fatiguing we could not have been fatiguing you could not have been fatiguing they could not have been fatiguing
Interrogative form
Simple form
could I fatigue? could you fatigue? could she fatigue? could we fatigue? could you fatigue? could they fatigue?
V-ing form
could I be fatiguing? could you be fatiguing? could she be fatiguing? could we be fatiguing? could you be fatiguing? could they be fatiguing?
Perfect
could I have fatigued? could you have fatigued? could she have fatigued? could we have fatigued? could you have fatigued? could they have fatigued?
V-ing perfect
could I have been fatiguing? could you have been fatiguing? could she have been fatiguing? could we have been fatiguing? could you have been fatiguing? could they have been fatiguing?
Interro-negative form
Simple form
could I not fatigue? could you not fatigue? could she not fatigue? could we not fatigue? could you not fatigue? could they not fatigue?
V-ing form
could I not be fatiguing? could you not be fatiguing? could she not be fatiguing? could we not be fatiguing? could you not be fatiguing? could they not be fatiguing?
Perfect
could I not have fatigued? could you not have fatigued? could she not have fatigued? could we not have fatigued? could you not have fatigued? could they not have fatigued?
V-ing perfect
could I not have been fatiguing? could you not have been fatiguing? could she not have been fatiguing? could we not have been fatiguing? could you not have been fatiguing? could they not have been fatiguing?