I can execute you can execute she can execute we can execute you can execute they can execute
V-ing form
I can be executing you can be executing she can be executing we can be executing you can be executing they can be executing
Perfect
I can have executed you can have executed she can have executed we can have executed you can have executed they can have executed
V-ing perfect
I can have been executing you can have been executing she can have been executing we can have been executing you can have been executing they can have been executing
Negation
Simple form
I cannot execute you cannot execute she cannot execute we cannot execute you cannot execute they cannot execute
V-ing form
I cannot be executing you cannot be executing she cannot be executing we cannot be executing you cannot be executing they cannot be executing
Perfect
I cannot have executed you cannot have executed she cannot have executed we cannot have executed you cannot have executed they cannot have executed
V-ing perfect
I cannot have been executing you cannot have been executing she cannot have been executing we cannot have been executing you cannot have been executing they cannot have been executing
Interrogative form
Simple form
can I execute? can you execute? can she execute? can we execute? can you execute? can they execute?
V-ing form
can I be executing? can you be executing? can she be executing? can we be executing? can you be executing? can they be executing?
Perfect
can I have executed? can you have executed? can she have executed? can we have executed? can you have executed? can they have executed?
V-ing perfect
can I have been executing? can you have been executing? can she have been executing? can we have been executing? can you have been executing? can they have been executing?
Interro-negative form
Simple form
can I not execute? can you not execute? can she not execute? can we not execute? can you not execute? can they not execute?
V-ing form
can I not be executing? can you not be executing? can she not be executing? can we not be executing? can you not be executing? can they not be executing?
Perfect
can I not have executed? can you not have executed? can she not have executed? can we not have executed? can you not have executed? can they not have executed?
V-ing perfect
can I not have been executing? can you not have been executing? can she not have been executing? can we not have been executing? can you not have been executing? can they not have been executing?