I can sing you can sing she can sing we can sing you can sing they can sing
V-ing form
I can be singing you can be singing she can be singing we can be singing you can be singing they can be singing
Perfect
I can have sung you can have sung she can have sung we can have sung you can have sung they can have sung
V-ing perfect
I can have been singing you can have been singing she can have been singing we can have been singing you can have been singing they can have been singing
Negation
Simple form
I can't sing you can't sing she can't sing we can't sing you can't sing they can't sing
V-ing form
I can't be singing you can't be singing she can't be singing we can't be singing you can't be singing they can't be singing
Perfect
I can't have sung you can't have sung she can't have sung we can't have sung you can't have sung they can't have sung
V-ing perfect
I can't have been singing you can't have been singing she can't have been singing we can't have been singing you can't have been singing they can't have been singing
Interrogative form
Simple form
can I sing? can you sing? can she sing? can we sing? can you sing? can they sing?
V-ing form
can I be singing? can you be singing? can she be singing? can we be singing? can you be singing? can they be singing?
Perfect
can I have sung? can you have sung? can she have sung? can we have sung? can you have sung? can they have sung?
V-ing perfect
can I have been singing? can you have been singing? can she have been singing? can we have been singing? can you have been singing? can they have been singing?
Interro-negative form
Simple form
can't I sing? can't you sing? can't she sing? can't we sing? can't you sing? can't they sing?
V-ing form
can't I be singing? can't you be singing? can't she be singing? can't we be singing? can't you be singing? can't they be singing?
Perfect
can't I have sung? can't you have sung? can't she have sung? can't we have sung? can't you have sung? can't they have sung?
V-ing perfect
can't I have been singing? can't you have been singing? can't she have been singing? can't we have been singing? can't you have been singing? can't they have been singing?