English verb conjugation
COULD PURIFY

Regular verb: purify - purified - purified

Affirmation

Simple form	V-ing form
I could purify you could purify she could purify we could purify you could purify they could purify	I could be purifying you could be purifying she could be purifying we could be purifying you could be purifying they could be purifying
Perfect	V-ing perfect
I could have purified you could have purified she could have purified we could have purified you could have purified they could have purified	I could have been purifying you could have been purifying she could have been purifying we could have been purifying you could have been purifying they could have been purifying

Negation

Simple form	V-ing form
I couldn't purify you couldn't purify she couldn't purify we couldn't purify you couldn't purify they couldn't purify	I couldn't be purifying you couldn't be purifying she couldn't be purifying we couldn't be purifying you couldn't be purifying they couldn't be purifying
Perfect	V-ing perfect
I couldn't have purified you couldn't have purified she couldn't have purified we couldn't have purified you couldn't have purified they couldn't have purified	I couldn't have been purifying you couldn't have been purifying she couldn't have been purifying we couldn't have been purifying you couldn't have been purifying they couldn't have been purifying

Interrogative form

Simple form	V-ing form
could I purify? could you purify? could she purify? could we purify? could you purify? could they purify?	could I be purifying? could you be purifying? could she be purifying? could we be purifying? could you be purifying? could they be purifying?
Perfect	V-ing perfect
could I have purified? could you have purified? could she have purified? could we have purified? could you have purified? could they have purified?	could I have been purifying? could you have been purifying? could she have been purifying? could we have been purifying? could you have been purifying? could they have been purifying?

Interro-negative form

Simple form	V-ing form
couldn't I purify? couldn't you purify? couldn't she purify? couldn't we purify? couldn't you purify? couldn't they purify?	couldn't I be purifying? couldn't you be purifying? couldn't she be purifying? couldn't we be purifying? couldn't you be purifying? couldn't they be purifying?
Perfect	V-ing perfect
couldn't I have purified? couldn't you have purified? couldn't she have purified? couldn't we have purified? couldn't you have purified? couldn't they have purified?	couldn't I have been purifying? couldn't you have been purifying? couldn't she have been purifying? couldn't we have been purifying? couldn't you have been purifying? couldn't they have been purifying?