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