I can vary you can vary he can vary we can vary you can vary they can vary
V-ing form
I can be varying you can be varying he can be varying we can be varying you can be varying they can be varying
Perfect
I can have varied you can have varied he can have varied we can have varied you can have varied they can have varied
V-ing perfect
I can have been varying you can have been varying he can have been varying we can have been varying you can have been varying they can have been varying
Negation
Simple form
I can't vary you can't vary he can't vary we can't vary you can't vary they can't vary
V-ing form
I can't be varying you can't be varying he can't be varying we can't be varying you can't be varying they can't be varying
Perfect
I can't have varied you can't have varied he can't have varied we can't have varied you can't have varied they can't have varied
V-ing perfect
I can't have been varying you can't have been varying he can't have been varying we can't have been varying you can't have been varying they can't have been varying
Interrogative form
Simple form
can I vary? can you vary? can he vary? can we vary? can you vary? can they vary?
V-ing form
can I be varying? can you be varying? can he be varying? can we be varying? can you be varying? can they be varying?
Perfect
can I have varied? can you have varied? can he have varied? can we have varied? can you have varied? can they have varied?
V-ing perfect
can I have been varying? can you have been varying? can he have been varying? can we have been varying? can you have been varying? can they have been varying?
Interro-negative form
Simple form
can't I vary? can't you vary? can't he vary? can't we vary? can't you vary? can't they vary?
V-ing form
can't I be varying? can't you be varying? can't he be varying? can't we be varying? can't you be varying? can't they be varying?
Perfect
can't I have varied? can't you have varied? can't he have varied? can't we have varied? can't you have varied? can't they have varied?
V-ing perfect
can't I have been varying? can't you have been varying? can't he have been varying? can't we have been varying? can't you have been varying? can't they have been varying?