English verb conjugation
CAN SING

Irregular verb: sing - sang - sung

Affirmation

Simple form	V-ing form
I can sing you can sing he can sing we can sing you can sing they can sing	I can be singing you can be singing he can be singing we can be singing you can be singing they can be singing
Perfect	V-ing perfect
I can have sung you can have sung he can have sung we can have sung you can have sung they can have sung	I can have been singing you can have been singing he can have been singing we can have been singing you can have been singing they can have been singing

Negation

Simple form	V-ing form
I cannot sing you cannot sing he cannot sing we cannot sing you cannot sing they cannot sing	I cannot be singing you cannot be singing he cannot be singing we cannot be singing you cannot be singing they cannot be singing
Perfect	V-ing perfect
I cannot have sung you cannot have sung he cannot have sung we cannot have sung you cannot have sung they cannot have sung	I cannot have been singing you cannot have been singing he cannot have been singing we cannot have been singing you cannot have been singing they cannot have been singing

Interrogative form

Simple form	V-ing form
can I sing? can you sing? can he sing? can we sing? can you sing? can they sing?	can I be singing? can you be singing? can he be singing? can we be singing? can you be singing? can they be singing?
Perfect	V-ing perfect
can I have sung? can you have sung? can he have sung? can we have sung? can you have sung? can they have sung?	can I have been singing? can you have been singing? can he have been singing? can we have been singing? can you have been singing? can they have been singing?

Interro-negative form

Simple form	V-ing form
can I not sing? can you not sing? can he not sing? can we not sing? can you not sing? can they not sing?	can I not be singing? can you not be singing? can he not be singing? can we not be singing? can you not be singing? can they not be singing?
Perfect	V-ing perfect
can I not have sung? can you not have sung? can he not have sung? can we not have sung? can you not have sung? can they not have sung?	can I not have been singing? can you not have been singing? can he not have been singing? can we not have been singing? can you not have been singing? can they not have been singing?