I could examine you could examine he could examine we could examine you could examine they could examine
Forma con V-ing
I could be examining you could be examining he could be examining we could be examining you could be examining they could be examining
Perfecto
I could have examined you could have examined he could have examined we could have examined you could have examined they could have examined
Perfecto con V-ing
I could have been examining you could have been examining he could have been examining we could have been examining you could have been examining they could have been examining
Negación
Forma simple
I couldn't examine you couldn't examine he couldn't examine we couldn't examine you couldn't examine they couldn't examine
Forma con V-ing
I couldn't be examining you couldn't be examining he couldn't be examining we couldn't be examining you couldn't be examining they couldn't be examining
Perfecto
I couldn't have examined you couldn't have examined he couldn't have examined we couldn't have examined you couldn't have examined they couldn't have examined
Perfecto con V-ing
I couldn't have been examining you couldn't have been examining he couldn't have been examining we couldn't have been examining you couldn't have been examining they couldn't have been examining
Forma interrogativa
Forma simple
could I examine? could you examine? could he examine? could we examine? could you examine? could they examine?
Forma con V-ing
could I be examining? could you be examining? could he be examining? could we be examining? could you be examining? could they be examining?
Perfecto
could I have examined? could you have examined? could he have examined? could we have examined? could you have examined? could they have examined?
Perfecto con V-ing
could I have been examining? could you have been examining? could he have been examining? could we have been examining? could you have been examining? could they have been examining?
Forma interro-negativa
Forma simple
couldn't I examine? couldn't you examine? couldn't he examine? couldn't we examine? couldn't you examine? couldn't they examine?
Forma con V-ing
couldn't I be examining? couldn't you be examining? couldn't he be examining? couldn't we be examining? couldn't you be examining? couldn't they be examining?
Perfecto
couldn't I have examined? couldn't you have examined? couldn't he have examined? couldn't we have examined? couldn't you have examined? couldn't they have examined?
Perfecto con V-ing
couldn't I have been examining? couldn't you have been examining? couldn't he have been examining? couldn't we have been examining? couldn't you have been examining? couldn't they have been examining?