I can tweak you can tweak she can tweak we can tweak you can tweak they can tweak
V-ing form
I can be tweaking you can be tweaking she can be tweaking we can be tweaking you can be tweaking they can be tweaking
Perfect
I can have tweaked you can have tweaked she 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 she can have been tweaking we can have been tweaking you can have been tweaking they can have been tweaking
Negation
Simple form
I can't tweak you can't tweak she can't tweak we can't tweak you can't tweak they can't tweak
V-ing form
I can't be tweaking you can't be tweaking she can't be tweaking we can't be tweaking you can't be tweaking they can't be tweaking
Perfect
I can't have tweaked you can't have tweaked she can't have tweaked we can't have tweaked you can't have tweaked they can't have tweaked
V-ing perfect
I can't have been tweaking you can't have been tweaking she can't have been tweaking we can't have been tweaking you can't have been tweaking they can't have been tweaking
Interrogative form
Simple form
can I tweak? can you tweak? can she tweak? can we tweak? can you tweak? can they tweak?
V-ing form
can I be tweaking? can you be tweaking? can she be tweaking? can we be tweaking? can you be tweaking? can they be tweaking?
Perfect
can I have tweaked? can you have tweaked? can she 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 she have been tweaking? can we have been tweaking? can you have been tweaking? can they have been tweaking?
Interro-negative form
Simple form
can't I tweak? can't you tweak? can't she tweak? can't we tweak? can't you tweak? can't they tweak?
V-ing form
can't I be tweaking? can't you be tweaking? can't she be tweaking? can't we be tweaking? can't you be tweaking? can't they be tweaking?
Perfect
can't I have tweaked? can't you have tweaked? can't she have tweaked? can't we have tweaked? can't you have tweaked? can't they have tweaked?
V-ing perfect
can't I have been tweaking? can't you have been tweaking? can't she have been tweaking? can't we have been tweaking? can't you have been tweaking? can't they have been tweaking?