Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could roar roar you could roar roar he could roar roar we could roar roar you could roar roar they could roar roar
V-ing form
I could be roar roaring you could be roar roaring he could be roar roaring we could be roar roaring you could be roar roaring they could be roar roaring
Perfect
I could have roar roared you could have roar roared he could have roar roared we could have roar roared you could have roar roared they could have roar roared
V-ing perfect
I could have been roar roaring you could have been roar roaring he could have been roar roaring we could have been roar roaring you could have been roar roaring they could have been roar roaring
Negation
Simple form
I could not roar roar you could not roar roar he could not roar roar we could not roar roar you could not roar roar they could not roar roar
V-ing form
I could not be roar roaring you could not be roar roaring he could not be roar roaring we could not be roar roaring you could not be roar roaring they could not be roar roaring
Perfect
I could not have roar roared you could not have roar roared he could not have roar roared we could not have roar roared you could not have roar roared they could not have roar roared
V-ing perfect
I could not have been roar roaring you could not have been roar roaring he could not have been roar roaring we could not have been roar roaring you could not have been roar roaring they could not have been roar roaring
Interrogative form
Simple form
could I roar roar? could you roar roar? could he roar roar? could we roar roar? could you roar roar? could they roar roar?
V-ing form
could I be roar roaring? could you be roar roaring? could he be roar roaring? could we be roar roaring? could you be roar roaring? could they be roar roaring?
Perfect
could I have roar roared? could you have roar roared? could he have roar roared? could we have roar roared? could you have roar roared? could they have roar roared?
V-ing perfect
could I have been roar roaring? could you have been roar roaring? could he have been roar roaring? could we have been roar roaring? could you have been roar roaring? could they have been roar roaring?
Interro-negative form
Simple form
could I not roar roar? could you not roar roar? could he not roar roar? could we not roar roar? could you not roar roar? could they not roar roar?
V-ing form
could I not be roar roaring? could you not be roar roaring? could he not be roar roaring? could we not be roar roaring? could you not be roar roaring? could they not be roar roaring?
Perfect
could I not have roar roared? could you not have roar roared? could he not have roar roared? could we not have roar roared? could you not have roar roared? could they not have roar roared?
V-ing perfect
could I not have been roar roaring? could you not have been roar roaring? could he not have been roar roaring? could we not have been roar roaring? could you not have been roar roaring? could they not have been roar roaring?