I can quit you can quit he can quit we can quit you can quit they can quit
V-ing form
I can be quitting you can be quitting he can be quitting we can be quitting you can be quitting they can be quitting
Perfect
I can have quit you can have quit he can have quit we can have quit you can have quit they can have quit
V-ing perfect
I can have been quitting you can have been quitting he can have been quitting we can have been quitting you can have been quitting they can have been quitting
Negation
Simple form
I cannot quit you cannot quit he cannot quit we cannot quit you cannot quit they cannot quit
V-ing form
I cannot be quitting you cannot be quitting he cannot be quitting we cannot be quitting you cannot be quitting they cannot be quitting
Perfect
I cannot have quit you cannot have quit he cannot have quit we cannot have quit you cannot have quit they cannot have quit
V-ing perfect
I cannot have been quitting you cannot have been quitting he cannot have been quitting we cannot have been quitting you cannot have been quitting they cannot have been quitting
Interrogative form
Simple form
can I quit? can you quit? can he quit? can we quit? can you quit? can they quit?
V-ing form
can I be quitting? can you be quitting? can he be quitting? can we be quitting? can you be quitting? can they be quitting?
Perfect
can I have quit? can you have quit? can he have quit? can we have quit? can you have quit? can they have quit?
V-ing perfect
can I have been quitting? can you have been quitting? can he have been quitting? can we have been quitting? can you have been quitting? can they have been quitting?
Interro-negative form
Simple form
can I not quit? can you not quit? can he not quit? can we not quit? can you not quit? can they not quit?
V-ing form
can I not be quitting? can you not be quitting? can he not be quitting? can we not be quitting? can you not be quitting? can they not be quitting?
Perfect
can I not have quit? can you not have quit? can he not have quit? can we not have quit? can you not have quit? can they not have quit?
V-ing perfect
can I not have been quitting? can you not have been quitting? can he not have been quitting? can we not have been quitting? can you not have been quitting? can they not have been quitting?