I can crowd you can crowd he can crowd we can crowd you can crowd they can crowd
V-ing form
I can be crowding you can be crowding he can be crowding we can be crowding you can be crowding they can be crowding
Perfect
I can have crowded you can have crowded he can have crowded we can have crowded you can have crowded they can have crowded
V-ing perfect
I can have been crowding you can have been crowding he can have been crowding we can have been crowding you can have been crowding they can have been crowding
Negation
Simple form
I can't crowd you can't crowd he can't crowd we can't crowd you can't crowd they can't crowd
V-ing form
I can't be crowding you can't be crowding he can't be crowding we can't be crowding you can't be crowding they can't be crowding
Perfect
I can't have crowded you can't have crowded he can't have crowded we can't have crowded you can't have crowded they can't have crowded
V-ing perfect
I can't have been crowding you can't have been crowding he can't have been crowding we can't have been crowding you can't have been crowding they can't have been crowding
Interrogative form
Simple form
can I crowd? can you crowd? can he crowd? can we crowd? can you crowd? can they crowd?
V-ing form
can I be crowding? can you be crowding? can he be crowding? can we be crowding? can you be crowding? can they be crowding?
Perfect
can I have crowded? can you have crowded? can he have crowded? can we have crowded? can you have crowded? can they have crowded?
V-ing perfect
can I have been crowding? can you have been crowding? can he have been crowding? can we have been crowding? can you have been crowding? can they have been crowding?
Interro-negative form
Simple form
can't I crowd? can't you crowd? can't he crowd? can't we crowd? can't you crowd? can't they crowd?
V-ing form
can't I be crowding? can't you be crowding? can't he be crowding? can't we be crowding? can't you be crowding? can't they be crowding?
Perfect
can't I have crowded? can't you have crowded? can't he have crowded? can't we have crowded? can't you have crowded? can't they have crowded?
V-ing perfect
can't I have been crowding? can't you have been crowding? can't he have been crowding? can't we have been crowding? can't you have been crowding? can't they have been crowding?