I can succumb you can succumb she can succumb we can succumb you can succumb they can succumb
V-ing form
I can be succumbing you can be succumbing she can be succumbing we can be succumbing you can be succumbing they can be succumbing
Perfect
I can have succumbed you can have succumbed she can have succumbed we can have succumbed you can have succumbed they can have succumbed
V-ing perfect
I can have been succumbing you can have been succumbing she can have been succumbing we can have been succumbing you can have been succumbing they can have been succumbing
Negation
Simple form
I can't succumb you can't succumb she can't succumb we can't succumb you can't succumb they can't succumb
V-ing form
I can't be succumbing you can't be succumbing she can't be succumbing we can't be succumbing you can't be succumbing they can't be succumbing
Perfect
I can't have succumbed you can't have succumbed she can't have succumbed we can't have succumbed you can't have succumbed they can't have succumbed
V-ing perfect
I can't have been succumbing you can't have been succumbing she can't have been succumbing we can't have been succumbing you can't have been succumbing they can't have been succumbing
Interrogative form
Simple form
can I succumb? can you succumb? can she succumb? can we succumb? can you succumb? can they succumb?
V-ing form
can I be succumbing? can you be succumbing? can she be succumbing? can we be succumbing? can you be succumbing? can they be succumbing?
Perfect
can I have succumbed? can you have succumbed? can she have succumbed? can we have succumbed? can you have succumbed? can they have succumbed?
V-ing perfect
can I have been succumbing? can you have been succumbing? can she have been succumbing? can we have been succumbing? can you have been succumbing? can they have been succumbing?
Interro-negative form
Simple form
can't I succumb? can't you succumb? can't she succumb? can't we succumb? can't you succumb? can't they succumb?
V-ing form
can't I be succumbing? can't you be succumbing? can't she be succumbing? can't we be succumbing? can't you be succumbing? can't they be succumbing?
Perfect
can't I have succumbed? can't you have succumbed? can't she have succumbed? can't we have succumbed? can't you have succumbed? can't they have succumbed?
V-ing perfect
can't I have been succumbing? can't you have been succumbing? can't she have been succumbing? can't we have been succumbing? can't you have been succumbing? can't they have been succumbing?