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