I can observe you can observe he can observe we can observe you can observe they can observe
Forme en V-ing
I can be observing you can be observing he can be observing we can be observing you can be observing they can be observing
Perfect
I can have observed you can have observed he can have observed we can have observed you can have observed they can have observed
Perfect en V-ing
I can have been observing you can have been observing he can have been observing we can have been observing you can have been observing they can have been observing
Négation
Forme simple
I can't observe you can't observe he can't observe we can't observe you can't observe they can't observe
Forme en V-ing
I can't be observing you can't be observing he can't be observing we can't be observing you can't be observing they can't be observing
Perfect
I can't have observed you can't have observed he can't have observed we can't have observed you can't have observed they can't have observed
Perfect en V-ing
I can't have been observing you can't have been observing he can't have been observing we can't have been observing you can't have been observing they can't have been observing
Forme interrogative
Forme simple
can I observe? can you observe? can he observe? can we observe? can you observe? can they observe?
Forme en V-ing
can I be observing? can you be observing? can he be observing? can we be observing? can you be observing? can they be observing?
Perfect
can I have observed? can you have observed? can he have observed? can we have observed? can you have observed? can they have observed?
Perfect en V-ing
can I have been observing? can you have been observing? can he have been observing? can we have been observing? can you have been observing? can they have been observing?
Forme interro-négative
Forme simple
can't I observe? can't you observe? can't he observe? can't we observe? can't you observe? can't they observe?
Forme en V-ing
can't I be observing? can't you be observing? can't he be observing? can't we be observing? can't you be observing? can't they be observing?
Perfect
can't I have observed? can't you have observed? can't he have observed? can't we have observed? can't you have observed? can't they have observed?
Perfect en V-ing
can't I have been observing? can't you have been observing? can't he have been observing? can't we have been observing? can't you have been observing? can't they have been observing?