I must despair you must despair he must despair we must despair you must despair they must despair
V-ing form
I must be despairing you must be despairing he must be despairing we must be despairing you must be despairing they must be despairing
Perfect
I must have despaired you must have despaired he must have despaired we must have despaired you must have despaired they must have despaired
V-ing perfect
I must have been despairing you must have been despairing he must have been despairing we must have been despairing you must have been despairing they must have been despairing
Negation
Simple form
I must not despair you must not despair he must not despair we must not despair you must not despair they must not despair
V-ing form
I must not be despairing you must not be despairing he must not be despairing we must not be despairing you must not be despairing they must not be despairing
Perfect
I must not have despaired you must not have despaired he must not have despaired we must not have despaired you must not have despaired they must not have despaired
V-ing perfect
I must not have been despairing you must not have been despairing he must not have been despairing we must not have been despairing you must not have been despairing they must not have been despairing
Interrogative form
Simple form
must I despair? must you despair? must he despair? must we despair? must you despair? must they despair?
V-ing form
must I be despairing? must you be despairing? must he be despairing? must we be despairing? must you be despairing? must they be despairing?
Perfect
must I have despaired? must you have despaired? must he have despaired? must we have despaired? must you have despaired? must they have despaired?
V-ing perfect
must I have been despairing? must you have been despairing? must he have been despairing? must we have been despairing? must you have been despairing? must they have been despairing?
Interro-negative form
Simple form
must I not despair? must you not despair? must he not despair? must we not despair? must you not despair? must they not despair?
V-ing form
must I not be despairing? must you not be despairing? must he not be despairing? must we not be despairing? must you not be despairing? must they not be despairing?
Perfect
must I not have despaired? must you not have despaired? must he not have despaired? must we not have despaired? must you not have despaired? must they not have despaired?
V-ing perfect
must I not have been despairing? must you not have been despairing? must he not have been despairing? must we not have been despairing? must you not have been despairing? must they not have been despairing?