I can crumple you can crumple he can crumple we can crumple you can crumple they can crumple
V-ing form
I can be crumpling you can be crumpling he can be crumpling we can be crumpling you can be crumpling they can be crumpling
Perfect
I can have crumpled you can have crumpled he can have crumpled we can have crumpled you can have crumpled they can have crumpled
V-ing perfect
I can have been crumpling you can have been crumpling he can have been crumpling we can have been crumpling you can have been crumpling they can have been crumpling
Negation
Simple form
I can't crumple you can't crumple he can't crumple we can't crumple you can't crumple they can't crumple
V-ing form
I can't be crumpling you can't be crumpling he can't be crumpling we can't be crumpling you can't be crumpling they can't be crumpling
Perfect
I can't have crumpled you can't have crumpled he can't have crumpled we can't have crumpled you can't have crumpled they can't have crumpled
V-ing perfect
I can't have been crumpling you can't have been crumpling he can't have been crumpling we can't have been crumpling you can't have been crumpling they can't have been crumpling
Interrogative form
Simple form
can I crumple? can you crumple? can he crumple? can we crumple? can you crumple? can they crumple?
V-ing form
can I be crumpling? can you be crumpling? can he be crumpling? can we be crumpling? can you be crumpling? can they be crumpling?
Perfect
can I have crumpled? can you have crumpled? can he have crumpled? can we have crumpled? can you have crumpled? can they have crumpled?
V-ing perfect
can I have been crumpling? can you have been crumpling? can he have been crumpling? can we have been crumpling? can you have been crumpling? can they have been crumpling?
Interro-negative form
Simple form
can't I crumple? can't you crumple? can't he crumple? can't we crumple? can't you crumple? can't they crumple?
V-ing form
can't I be crumpling? can't you be crumpling? can't he be crumpling? can't we be crumpling? can't you be crumpling? can't they be crumpling?
Perfect
can't I have crumpled? can't you have crumpled? can't he have crumpled? can't we have crumpled? can't you have crumpled? can't they have crumpled?
V-ing perfect
can't I have been crumpling? can't you have been crumpling? can't he have been crumpling? can't we have been crumpling? can't you have been crumpling? can't they have been crumpling?