English verb conjugation
COULD PURCHASE

Regular verb: purchase - purchased - purchased

Affirmation

Simple form	V-ing form
I could purchase you could purchase she could purchase we could purchase you could purchase they could purchase	I could be purchasing you could be purchasing she could be purchasing we could be purchasing you could be purchasing they could be purchasing
Perfect	V-ing perfect
I could have purchased you could have purchased she could have purchased we could have purchased you could have purchased they could have purchased	I could have been purchasing you could have been purchasing she could have been purchasing we could have been purchasing you could have been purchasing they could have been purchasing

Negation

Simple form	V-ing form
I couldn't purchase you couldn't purchase she couldn't purchase we couldn't purchase you couldn't purchase they couldn't purchase	I couldn't be purchasing you couldn't be purchasing she couldn't be purchasing we couldn't be purchasing you couldn't be purchasing they couldn't be purchasing
Perfect	V-ing perfect
I couldn't have purchased you couldn't have purchased she couldn't have purchased we couldn't have purchased you couldn't have purchased they couldn't have purchased	I couldn't have been purchasing you couldn't have been purchasing she couldn't have been purchasing we couldn't have been purchasing you couldn't have been purchasing they couldn't have been purchasing

Interrogative form

Simple form	V-ing form
could I purchase? could you purchase? could she purchase? could we purchase? could you purchase? could they purchase?	could I be purchasing? could you be purchasing? could she be purchasing? could we be purchasing? could you be purchasing? could they be purchasing?
Perfect	V-ing perfect
could I have purchased? could you have purchased? could she have purchased? could we have purchased? could you have purchased? could they have purchased?	could I have been purchasing? could you have been purchasing? could she have been purchasing? could we have been purchasing? could you have been purchasing? could they have been purchasing?

Interro-negative form

Simple form	V-ing form
couldn't I purchase? couldn't you purchase? couldn't she purchase? couldn't we purchase? couldn't you purchase? couldn't they purchase?	couldn't I be purchasing? couldn't you be purchasing? couldn't she be purchasing? couldn't we be purchasing? couldn't you be purchasing? couldn't they be purchasing?
Perfect	V-ing perfect
couldn't I have purchased? couldn't you have purchased? couldn't she have purchased? couldn't we have purchased? couldn't you have purchased? couldn't they have purchased?	couldn't I have been purchasing? couldn't you have been purchasing? couldn't she have been purchasing? couldn't we have been purchasing? couldn't you have been purchasing? couldn't they have been purchasing?