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 can't execute you can't execute she can't execute we can't execute you can't execute they can't execute
V-ing form
I can't be executing you can't be executing she can't be executing we can't be executing you can't be executing they can't be executing
Perfect
I can't have executed you can't have executed she can't have executed we can't have executed you can't have executed they can't have executed
V-ing perfect
I can't have been executing you can't have been executing she can't have been executing we can't have been executing you can't have been executing they can't 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't I execute? can't you execute? can't she execute? can't we execute? can't you execute? can't they execute?
V-ing form
can't I be executing? can't you be executing? can't she be executing? can't we be executing? can't you be executing? can't they be executing?
Perfect
can't I have executed? can't you have executed? can't she have executed? can't we have executed? can't you have executed? can't they have executed?
V-ing perfect
can't I have been executing? can't you have been executing? can't she have been executing? can't we have been executing? can't you have been executing? can't they have been executing?