I can landmark you can landmark she can landmark we can landmark you can landmark they can landmark
V-ing form
I can be landmarking you can be landmarking she can be landmarking we can be landmarking you can be landmarking they can be landmarking
Perfect
I can have landmarked you can have landmarked she can have landmarked we can have landmarked you can have landmarked they can have landmarked
V-ing perfect
I can have been landmarking you can have been landmarking she can have been landmarking we can have been landmarking you can have been landmarking they can have been landmarking
Negation
Simple form
I can't landmark you can't landmark she can't landmark we can't landmark you can't landmark they can't landmark
V-ing form
I can't be landmarking you can't be landmarking she can't be landmarking we can't be landmarking you can't be landmarking they can't be landmarking
Perfect
I can't have landmarked you can't have landmarked she can't have landmarked we can't have landmarked you can't have landmarked they can't have landmarked
V-ing perfect
I can't have been landmarking you can't have been landmarking she can't have been landmarking we can't have been landmarking you can't have been landmarking they can't have been landmarking
Interrogative form
Simple form
can I landmark? can you landmark? can she landmark? can we landmark? can you landmark? can they landmark?
V-ing form
can I be landmarking? can you be landmarking? can she be landmarking? can we be landmarking? can you be landmarking? can they be landmarking?
Perfect
can I have landmarked? can you have landmarked? can she have landmarked? can we have landmarked? can you have landmarked? can they have landmarked?
V-ing perfect
can I have been landmarking? can you have been landmarking? can she have been landmarking? can we have been landmarking? can you have been landmarking? can they have been landmarking?
Interro-negative form
Simple form
can't I landmark? can't you landmark? can't she landmark? can't we landmark? can't you landmark? can't they landmark?
V-ing form
can't I be landmarking? can't you be landmarking? can't she be landmarking? can't we be landmarking? can't you be landmarking? can't they be landmarking?
Perfect
can't I have landmarked? can't you have landmarked? can't she have landmarked? can't we have landmarked? can't you have landmarked? can't they have landmarked?
V-ing perfect
can't I have been landmarking? can't you have been landmarking? can't she have been landmarking? can't we have been landmarking? can't you have been landmarking? can't they have been landmarking?