I can duck you can duck he can duck we can duck you can duck they can duck
Forma con V-ing
I can be ducking you can be ducking he can be ducking we can be ducking you can be ducking they can be ducking
Perfecto
I can have ducked you can have ducked he can have ducked we can have ducked you can have ducked they can have ducked
Perfecto con V-ing
I can have been ducking you can have been ducking he can have been ducking we can have been ducking you can have been ducking they can have been ducking
Negación
Forma simple
I can't duck you can't duck he can't duck we can't duck you can't duck they can't duck
Forma con V-ing
I can't be ducking you can't be ducking he can't be ducking we can't be ducking you can't be ducking they can't be ducking
Perfecto
I can't have ducked you can't have ducked he can't have ducked we can't have ducked you can't have ducked they can't have ducked
Perfecto con V-ing
I can't have been ducking you can't have been ducking he can't have been ducking we can't have been ducking you can't have been ducking they can't have been ducking
Forma interrogativa
Forma simple
can I duck? can you duck? can he duck? can we duck? can you duck? can they duck?
Forma con V-ing
can I be ducking? can you be ducking? can he be ducking? can we be ducking? can you be ducking? can they be ducking?
Perfecto
can I have ducked? can you have ducked? can he have ducked? can we have ducked? can you have ducked? can they have ducked?
Perfecto con V-ing
can I have been ducking? can you have been ducking? can he have been ducking? can we have been ducking? can you have been ducking? can they have been ducking?
Forma interro-negativa
Forma simple
can't I duck? can't you duck? can't he duck? can't we duck? can't you duck? can't they duck?
Forma con V-ing
can't I be ducking? can't you be ducking? can't he be ducking? can't we be ducking? can't you be ducking? can't they be ducking?
Perfecto
can't I have ducked? can't you have ducked? can't he have ducked? can't we have ducked? can't you have ducked? can't they have ducked?
Perfecto con V-ing
can't I have been ducking? can't you have been ducking? can't he have been ducking? can't we have been ducking? can't you have been ducking? can't they have been ducking?