I can fertilize you can fertilize he can fertilize we can fertilize you can fertilize they can fertilize
V-ing form
I can be fertilizing you can be fertilizing he can be fertilizing we can be fertilizing you can be fertilizing they can be fertilizing
Perfect
I can have fertilized you can have fertilized he can have fertilized we can have fertilized you can have fertilized they can have fertilized
V-ing perfect
I can have been fertilizing you can have been fertilizing he can have been fertilizing we can have been fertilizing you can have been fertilizing they can have been fertilizing
Negation
Simple form
I can't fertilize you can't fertilize he can't fertilize we can't fertilize you can't fertilize they can't fertilize
V-ing form
I can't be fertilizing you can't be fertilizing he can't be fertilizing we can't be fertilizing you can't be fertilizing they can't be fertilizing
Perfect
I can't have fertilized you can't have fertilized he can't have fertilized we can't have fertilized you can't have fertilized they can't have fertilized
V-ing perfect
I can't have been fertilizing you can't have been fertilizing he can't have been fertilizing we can't have been fertilizing you can't have been fertilizing they can't have been fertilizing
Interrogative form
Simple form
can I fertilize? can you fertilize? can he fertilize? can we fertilize? can you fertilize? can they fertilize?
V-ing form
can I be fertilizing? can you be fertilizing? can he be fertilizing? can we be fertilizing? can you be fertilizing? can they be fertilizing?
Perfect
can I have fertilized? can you have fertilized? can he have fertilized? can we have fertilized? can you have fertilized? can they have fertilized?
V-ing perfect
can I have been fertilizing? can you have been fertilizing? can he have been fertilizing? can we have been fertilizing? can you have been fertilizing? can they have been fertilizing?
Interro-negative form
Simple form
can't I fertilize? can't you fertilize? can't he fertilize? can't we fertilize? can't you fertilize? can't they fertilize?
V-ing form
can't I be fertilizing? can't you be fertilizing? can't he be fertilizing? can't we be fertilizing? can't you be fertilizing? can't they be fertilizing?
Perfect
can't I have fertilized? can't you have fertilized? can't he have fertilized? can't we have fertilized? can't you have fertilized? can't they have fertilized?
V-ing perfect
can't I have been fertilizing? can't you have been fertilizing? can't he have been fertilizing? can't we have been fertilizing? can't you have been fertilizing? can't they have been fertilizing?