I can crowd you can crowd she can crowd we can crowd you can crowd they can crowd
V-ing form
I can be crowding you can be crowding she can be crowding we can be crowding you can be crowding they can be crowding
Perfect
I can have crowded you can have crowded she 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 she can have been crowding we can have been crowding you can have been crowding they can have been crowding
Negation
Simple form
I cannot crowd you cannot crowd she cannot crowd we cannot crowd you cannot crowd they cannot crowd
V-ing form
I cannot be crowding you cannot be crowding she cannot be crowding we cannot be crowding you cannot be crowding they cannot be crowding
Perfect
I cannot have crowded you cannot have crowded she cannot have crowded we cannot have crowded you cannot have crowded they cannot have crowded
V-ing perfect
I cannot have been crowding you cannot have been crowding she cannot have been crowding we cannot have been crowding you cannot have been crowding they cannot have been crowding
Interrogative form
Simple form
can I crowd? can you crowd? can she crowd? can we crowd? can you crowd? can they crowd?
V-ing form
can I be crowding? can you be crowding? can she be crowding? can we be crowding? can you be crowding? can they be crowding?
Perfect
can I have crowded? can you have crowded? can she 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 she have been crowding? can we have been crowding? can you have been crowding? can they have been crowding?
Interro-negative form
Simple form
can I not crowd? can you not crowd? can she not crowd? can we not crowd? can you not crowd? can they not crowd?
V-ing form
can I not be crowding? can you not be crowding? can she not be crowding? can we not be crowding? can you not be crowding? can they not be crowding?
Perfect
can I not have crowded? can you not have crowded? can she not have crowded? can we not have crowded? can you not have crowded? can they not have crowded?
V-ing perfect
can I not have been crowding? can you not have been crowding? can she not have been crowding? can we not have been crowding? can you not have been crowding? can they not have been crowding?