I can weigh you can weigh he can weigh we can weigh you can weigh they can weigh
V-ing form
I can be weighing you can be weighing he can be weighing we can be weighing you can be weighing they can be weighing
Perfect
I can have weighed you can have weighed he can have weighed we can have weighed you can have weighed they can have weighed
V-ing perfect
I can have been weighing you can have been weighing he can have been weighing we can have been weighing you can have been weighing they can have been weighing
Negation
Simple form
I can't weigh you can't weigh he can't weigh we can't weigh you can't weigh they can't weigh
V-ing form
I can't be weighing you can't be weighing he can't be weighing we can't be weighing you can't be weighing they can't be weighing
Perfect
I can't have weighed you can't have weighed he can't have weighed we can't have weighed you can't have weighed they can't have weighed
V-ing perfect
I can't have been weighing you can't have been weighing he can't have been weighing we can't have been weighing you can't have been weighing they can't have been weighing
Interrogative form
Simple form
can I weigh? can you weigh? can he weigh? can we weigh? can you weigh? can they weigh?
V-ing form
can I be weighing? can you be weighing? can he be weighing? can we be weighing? can you be weighing? can they be weighing?
Perfect
can I have weighed? can you have weighed? can he have weighed? can we have weighed? can you have weighed? can they have weighed?
V-ing perfect
can I have been weighing? can you have been weighing? can he have been weighing? can we have been weighing? can you have been weighing? can they have been weighing?
Interro-negative form
Simple form
can't I weigh? can't you weigh? can't he weigh? can't we weigh? can't you weigh? can't they weigh?
V-ing form
can't I be weighing? can't you be weighing? can't he be weighing? can't we be weighing? can't you be weighing? can't they be weighing?
Perfect
can't I have weighed? can't you have weighed? can't he have weighed? can't we have weighed? can't you have weighed? can't they have weighed?
V-ing perfect
can't I have been weighing? can't you have been weighing? can't he have been weighing? can't we have been weighing? can't you have been weighing? can't they have been weighing?