English verb conjugation
COULD BUY

Irregular verb: buy - bought - bought

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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