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