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