English verb conjugation
CAN BUY

Irregular verb: buy - bought - bought

Affirmation

Simple form	V-ing form
I can buy you can buy he can buy we can buy you can buy they can buy	I can be buying you can be buying he can be buying we can be buying you can be buying they can be buying
Perfect	V-ing perfect
I can have bought you can have bought he can have bought we can have bought you can have bought they can have bought	I can have been buying you can have been buying he can have been buying we can have been buying you can have been buying they can have been buying

Negation

Simple form	V-ing form
I can't buy you can't buy he can't buy we can't buy you can't buy they can't buy	I can't be buying you can't be buying he can't be buying we can't be buying you can't be buying they can't be buying
Perfect	V-ing perfect
I can't have bought you can't have bought he can't have bought we can't have bought you can't have bought they can't have bought	I can't have been buying you can't have been buying he can't have been buying we can't have been buying you can't have been buying they can't have been buying

Interrogative form

Simple form	V-ing form
can I buy? can you buy? can he buy? can we buy? can you buy? can they buy?	can I be buying? can you be buying? can he be buying? can we be buying? can you be buying? can they be buying?
Perfect	V-ing perfect
can I have bought? can you have bought? can he have bought? can we have bought? can you have bought? can they have bought?	can I have been buying? can you have been buying? can he have been buying? can we have been buying? can you have been buying? can they have been buying?

Interro-negative form

Simple form	V-ing form
can't I buy? can't you buy? can't he buy? can't we buy? can't you buy? can't they buy?	can't I be buying? can't you be buying? can't he be buying? can't we be buying? can't you be buying? can't they be buying?
Perfect	V-ing perfect
can't I have bought? can't you have bought? can't he have bought? can't we have bought? can't you have bought? can't they have bought?	can't I have been buying? can't you have been buying? can't he have been buying? can't we have been buying? can't you have been buying? can't they have been buying?