I can slip you can slip he can slip we can slip you can slip they can slip
V-ing form
I can be slipping you can be slipping he can be slipping we can be slipping you can be slipping they can be slipping
Perfect
I can have slipped you can have slipped he can have slipped we can have slipped you can have slipped they can have slipped
V-ing perfect
I can have been slipping you can have been slipping he can have been slipping we can have been slipping you can have been slipping they can have been slipping
Negation
Simple form
I can't slip you can't slip he can't slip we can't slip you can't slip they can't slip
V-ing form
I can't be slipping you can't be slipping he can't be slipping we can't be slipping you can't be slipping they can't be slipping
Perfect
I can't have slipped you can't have slipped he can't have slipped we can't have slipped you can't have slipped they can't have slipped
V-ing perfect
I can't have been slipping you can't have been slipping he can't have been slipping we can't have been slipping you can't have been slipping they can't have been slipping
Interrogative form
Simple form
can I slip? can you slip? can he slip? can we slip? can you slip? can they slip?
V-ing form
can I be slipping? can you be slipping? can he be slipping? can we be slipping? can you be slipping? can they be slipping?
Perfect
can I have slipped? can you have slipped? can he have slipped? can we have slipped? can you have slipped? can they have slipped?
V-ing perfect
can I have been slipping? can you have been slipping? can he have been slipping? can we have been slipping? can you have been slipping? can they have been slipping?
Interro-negative form
Simple form
can't I slip? can't you slip? can't he slip? can't we slip? can't you slip? can't they slip?
V-ing form
can't I be slipping? can't you be slipping? can't he be slipping? can't we be slipping? can't you be slipping? can't they be slipping?
Perfect
can't I have slipped? can't you have slipped? can't he have slipped? can't we have slipped? can't you have slipped? can't they have slipped?
V-ing perfect
can't I have been slipping? can't you have been slipping? can't he have been slipping? can't we have been slipping? can't you have been slipping? can't they have been slipping?