Verbo regular: concentrate - concentrated - concentrated
Forma simple | Forma con V-ing |
I could concentrate you could concentrate he could concentrate we could concentrate you could concentrate they could concentrate | I could be concentrating you could be concentrating he could be concentrating we could be concentrating you could be concentrating they could be concentrating |
Perfecto | Perfecto con V-ing |
I could have concentrated you could have concentrated he could have concentrated we could have concentrated you could have concentrated they could have concentrated | I could have been concentrating you could have been concentrating he could have been concentrating we could have been concentrating you could have been concentrating they could have been concentrating |
Forma simple | Forma con V-ing |
I couldn't concentrate you couldn't concentrate he couldn't concentrate we couldn't concentrate you couldn't concentrate they couldn't concentrate | I couldn't be concentrating you couldn't be concentrating he couldn't be concentrating we couldn't be concentrating you couldn't be concentrating they couldn't be concentrating |
Perfecto | Perfecto con V-ing |
I couldn't have concentrated you couldn't have concentrated he couldn't have concentrated we couldn't have concentrated you couldn't have concentrated they couldn't have concentrated | I couldn't have been concentrating you couldn't have been concentrating he couldn't have been concentrating we couldn't have been concentrating you couldn't have been concentrating they couldn't have been concentrating |
Forma simple | Forma con V-ing |
could I concentrate? could you concentrate? could he concentrate? could we concentrate? could you concentrate? could they concentrate? | could I be concentrating? could you be concentrating? could he be concentrating? could we be concentrating? could you be concentrating? could they be concentrating? |
Perfecto | Perfecto con V-ing |
could I have concentrated? could you have concentrated? could he have concentrated? could we have concentrated? could you have concentrated? could they have concentrated? | could I have been concentrating? could you have been concentrating? could he have been concentrating? could we have been concentrating? could you have been concentrating? could they have been concentrating? |
Forma simple | Forma con V-ing |
couldn't I concentrate? couldn't you concentrate? couldn't he concentrate? couldn't we concentrate? couldn't you concentrate? couldn't they concentrate? | couldn't I be concentrating? couldn't you be concentrating? couldn't he be concentrating? couldn't we be concentrating? couldn't you be concentrating? couldn't they be concentrating? |
Perfecto | Perfecto con V-ing |
couldn't I have concentrated? couldn't you have concentrated? couldn't he have concentrated? couldn't we have concentrated? couldn't you have concentrated? couldn't they have concentrated? | couldn't I have been concentrating? couldn't you have been concentrating? couldn't he have been concentrating? couldn't we have been concentrating? couldn't you have been concentrating? couldn't they have been concentrating? |