I could bowl you could bowl he could bowl we could bowl you could bowl they could bowl
V-ing form
I could be bowling you could be bowling he could be bowling we could be bowling you could be bowling they could be bowling
Perfect
I could have bowled you could have bowled he could have bowled we could have bowled you could have bowled they could have bowled
V-ing perfect
I could have been bowling you could have been bowling he could have been bowling we could have been bowling you could have been bowling they could have been bowling
Negation
Simple form
I couldn't bowl you couldn't bowl he couldn't bowl we couldn't bowl you couldn't bowl they couldn't bowl
V-ing form
I couldn't be bowling you couldn't be bowling he couldn't be bowling we couldn't be bowling you couldn't be bowling they couldn't be bowling
Perfect
I couldn't have bowled you couldn't have bowled he couldn't have bowled we couldn't have bowled you couldn't have bowled they couldn't have bowled
V-ing perfect
I couldn't have been bowling you couldn't have been bowling he couldn't have been bowling we couldn't have been bowling you couldn't have been bowling they couldn't have been bowling
Interrogative form
Simple form
could I bowl? could you bowl? could he bowl? could we bowl? could you bowl? could they bowl?
V-ing form
could I be bowling? could you be bowling? could he be bowling? could we be bowling? could you be bowling? could they be bowling?
Perfect
could I have bowled? could you have bowled? could he have bowled? could we have bowled? could you have bowled? could they have bowled?
V-ing perfect
could I have been bowling? could you have been bowling? could he have been bowling? could we have been bowling? could you have been bowling? could they have been bowling?
Interro-negative form
Simple form
couldn't I bowl? couldn't you bowl? couldn't he bowl? couldn't we bowl? couldn't you bowl? couldn't they bowl?
V-ing form
couldn't I be bowling? couldn't you be bowling? couldn't he be bowling? couldn't we be bowling? couldn't you be bowling? couldn't they be bowling?
Perfect
couldn't I have bowled? couldn't you have bowled? couldn't he have bowled? couldn't we have bowled? couldn't you have bowled? couldn't they have bowled?
V-ing perfect
couldn't I have been bowling? couldn't you have been bowling? couldn't he have been bowling? couldn't we have been bowling? couldn't you have been bowling? couldn't they have been bowling?