could tweak
Regular verb: tweak - tweaked- tweaked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tweak
you could tweak
she could tweak
we could tweak
you could tweak
they could tweak 	I could be tweaking
you could be tweaking
she could be tweaking
we could be tweaking
you could be tweaking
they could be tweaking	I could have tweaked
you could have tweaked
she could have tweaked
we could have tweaked
you could have tweaked
they could have tweaked	I could have been tweaking
you could have been tweaking
she could have been tweaking
we could have been tweaking
you could have been tweaking
they could have been tweaking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't tweak
you couldn't tweak
she couldn't tweak
we couldn't tweak
you couldn't tweak
they couldn't tweak 	I couldn't be tweaking
you couldn't be tweaking
she couldn't be tweaking
we couldn't be tweaking
you couldn't be tweaking
they couldn't be tweaking	I couldn't have tweaked
you couldn't have tweaked
she couldn't have tweaked
we couldn't have tweaked
you couldn't have tweaked
they couldn't have tweaked	I couldn't have been tweaking
you couldn't have been tweaking
she couldn't have been tweaking
we couldn't have been tweaking
you couldn't have been tweaking
they couldn't have been tweaking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tweak?
could you tweak?
could she tweak?
could we tweak?
could you tweak?
could they tweak? 	could I be tweaking?
could you be tweaking?
could she be tweaking?
could we be tweaking?
could you be tweaking?
could they be tweaking? 	could I have tweaked?
could you have tweaked?
could she have tweaked?
could we have tweaked?
could you have tweaked?
could they have tweaked? 	could I have been tweaking?
could you have been tweaking?
could she have been tweaking?
could we have been tweaking?
could you have been tweaking?
could they have been tweaking? 	

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