I could tread you could tread she could tread we could tread you could tread they could tread
Forma con V-ing
I could be treading you could be treading she could be treading we could be treading you could be treading they could be treading
Perfecto
I could have trod, trodden you could have trod, trodden she could have trod, trodden we could have trod, trodden you could have trod, trodden they could have trod, trodden
Perfecto con V-ing
I could have been treading you could have been treading she could have been treading we could have been treading you could have been treading they could have been treading
Negación
Forma simple
I couldn't tread you couldn't tread she couldn't tread we couldn't tread you couldn't tread they couldn't tread
Forma con V-ing
I couldn't be treading you couldn't be treading she couldn't be treading we couldn't be treading you couldn't be treading they couldn't be treading
Perfecto
I couldn't have trod, trodden you couldn't have trod, trodden she couldn't have trod, trodden we couldn't have trod, trodden you couldn't have trod, trodden they couldn't have trod, trodden
Perfecto con V-ing
I couldn't have been treading you couldn't have been treading she couldn't have been treading we couldn't have been treading you couldn't have been treading they couldn't have been treading
Forma interrogativa
Forma simple
could I tread? could you tread? could she tread? could we tread? could you tread? could they tread?
Forma con V-ing
could I be treading? could you be treading? could she be treading? could we be treading? could you be treading? could they be treading?
Perfecto
could I have trod, trodden? could you have trod, trodden? could she have trod, trodden? could we have trod, trodden? could you have trod, trodden? could they have trod, trodden?
Perfecto con V-ing
could I have been treading? could you have been treading? could she have been treading? could we have been treading? could you have been treading? could they have been treading?
Forma interro-negativa
Forma simple
couldn't I tread? couldn't you tread? couldn't she tread? couldn't we tread? couldn't you tread? couldn't they tread?
Forma con V-ing
couldn't I be treading? couldn't you be treading? couldn't she be treading? couldn't we be treading? couldn't you be treading? couldn't they be treading?
Perfecto
couldn't I have trod, trodden? couldn't you have trod, trodden? couldn't she have trod, trodden? couldn't we have trod, trodden? couldn't you have trod, trodden? couldn't they have trod, trodden?
Perfecto con V-ing
couldn't I have been treading? couldn't you have been treading? couldn't she have been treading? couldn't we have been treading? couldn't you have been treading? couldn't they have been treading?