I can unload you can unload he can unload we can unload you can unload they can unload
V-ing form
I can be unloading you can be unloading he can be unloading we can be unloading you can be unloading they can be unloading
Perfect
I can have unloaded you can have unloaded he can have unloaded we can have unloaded you can have unloaded they can have unloaded
V-ing perfect
I can have been unloading you can have been unloading he can have been unloading we can have been unloading you can have been unloading they can have been unloading
Negation
Simple form
I can't unload you can't unload he can't unload we can't unload you can't unload they can't unload
V-ing form
I can't be unloading you can't be unloading he can't be unloading we can't be unloading you can't be unloading they can't be unloading
Perfect
I can't have unloaded you can't have unloaded he can't have unloaded we can't have unloaded you can't have unloaded they can't have unloaded
V-ing perfect
I can't have been unloading you can't have been unloading he can't have been unloading we can't have been unloading you can't have been unloading they can't have been unloading
Interrogative form
Simple form
can I unload? can you unload? can he unload? can we unload? can you unload? can they unload?
V-ing form
can I be unloading? can you be unloading? can he be unloading? can we be unloading? can you be unloading? can they be unloading?
Perfect
can I have unloaded? can you have unloaded? can he have unloaded? can we have unloaded? can you have unloaded? can they have unloaded?
V-ing perfect
can I have been unloading? can you have been unloading? can he have been unloading? can we have been unloading? can you have been unloading? can they have been unloading?
Interro-negative form
Simple form
can't I unload? can't you unload? can't he unload? can't we unload? can't you unload? can't they unload?
V-ing form
can't I be unloading? can't you be unloading? can't he be unloading? can't we be unloading? can't you be unloading? can't they be unloading?
Perfect
can't I have unloaded? can't you have unloaded? can't he have unloaded? can't we have unloaded? can't you have unloaded? can't they have unloaded?
V-ing perfect
can't I have been unloading? can't you have been unloading? can't he have been unloading? can't we have been unloading? can't you have been unloading? can't they have been unloading?