English verb conjugation
COULD EXECUTE

Regular verb: execute - executed - executed

Affirmation

Simple form	V-ing form
I could execute you could execute he could execute we could execute you could execute they could execute	I could be executing you could be executing he could be executing we could be executing you could be executing they could be executing
Perfect	V-ing perfect
I could have executed you could have executed he could have executed we could have executed you could have executed they could have executed	I could have been executing you could have been executing he could have been executing we could have been executing you could have been executing they could have been executing

Negation

Simple form	V-ing form
I could not execute you could not execute he could not execute we could not execute you could not execute they could not execute	I could not be executing you could not be executing he could not be executing we could not be executing you could not be executing they could not be executing
Perfect	V-ing perfect
I could not have executed you could not have executed he could not have executed we could not have executed you could not have executed they could not have executed	I could not have been executing you could not have been executing he could not have been executing we could not have been executing you could not have been executing they could not have been executing

Interrogative form

Simple form	V-ing form
could I execute? could you execute? could he execute? could we execute? could you execute? could they execute?	could I be executing? could you be executing? could he be executing? could we be executing? could you be executing? could they be executing?
Perfect	V-ing perfect
could I have executed? could you have executed? could he have executed? could we have executed? could you have executed? could they have executed?	could I have been executing? could you have been executing? could he have been executing? could we have been executing? could you have been executing? could they have been executing?

Interro-negative form

Simple form	V-ing form
could I not execute? could you not execute? could he not execute? could we not execute? could you not execute? could they not execute?	could I not be executing? could you not be executing? could he not be executing? could we not be executing? could you not be executing? could they not be executing?
Perfect	V-ing perfect
could I not have executed? could you not have executed? could he not have executed? could we not have executed? could you not have executed? could they not have executed?	could I not have been executing? could you not have been executing? could he not have been executing? could we not have been executing? could you not have been executing? could they not have been executing?