English verb conjugation
COULD NITRIFY

Regular verb: nitrify - nitrified - nitrified

Affirmation

Simple form	V-ing form
I could nitrify you could nitrify he could nitrify we could nitrify you could nitrify they could nitrify	I could be nitrifying you could be nitrifying he could be nitrifying we could be nitrifying you could be nitrifying they could be nitrifying
Perfect	V-ing perfect
I could have nitrified you could have nitrified he could have nitrified we could have nitrified you could have nitrified they could have nitrified	I could have been nitrifying you could have been nitrifying he could have been nitrifying we could have been nitrifying you could have been nitrifying they could have been nitrifying

Negation

Simple form	V-ing form
I couldn't nitrify you couldn't nitrify he couldn't nitrify we couldn't nitrify you couldn't nitrify they couldn't nitrify	I couldn't be nitrifying you couldn't be nitrifying he couldn't be nitrifying we couldn't be nitrifying you couldn't be nitrifying they couldn't be nitrifying
Perfect	V-ing perfect
I couldn't have nitrified you couldn't have nitrified he couldn't have nitrified we couldn't have nitrified you couldn't have nitrified they couldn't have nitrified	I couldn't have been nitrifying you couldn't have been nitrifying he couldn't have been nitrifying we couldn't have been nitrifying you couldn't have been nitrifying they couldn't have been nitrifying

Interrogative form

Simple form	V-ing form
could I nitrify? could you nitrify? could he nitrify? could we nitrify? could you nitrify? could they nitrify?	could I be nitrifying? could you be nitrifying? could he be nitrifying? could we be nitrifying? could you be nitrifying? could they be nitrifying?
Perfect	V-ing perfect
could I have nitrified? could you have nitrified? could he have nitrified? could we have nitrified? could you have nitrified? could they have nitrified?	could I have been nitrifying? could you have been nitrifying? could he have been nitrifying? could we have been nitrifying? could you have been nitrifying? could they have been nitrifying?

Interro-negative form

Simple form	V-ing form
couldn't I nitrify? couldn't you nitrify? couldn't he nitrify? couldn't we nitrify? couldn't you nitrify? couldn't they nitrify?	couldn't I be nitrifying? couldn't you be nitrifying? couldn't he be nitrifying? couldn't we be nitrifying? couldn't you be nitrifying? couldn't they be nitrifying?
Perfect	V-ing perfect
couldn't I have nitrified? couldn't you have nitrified? couldn't he have nitrified? couldn't we have nitrified? couldn't you have nitrified? couldn't they have nitrified?	couldn't I have been nitrifying? couldn't you have been nitrifying? couldn't he have been nitrifying? couldn't we have been nitrifying? couldn't you have been nitrifying? couldn't they have been nitrifying?