I could sire you could sire she could sire we could sire you could sire they could sire
Forma con V-ing
I could be siring you could be siring she could be siring we could be siring you could be siring they could be siring
Perfecto
I could have sired you could have sired she could have sired we could have sired you could have sired they could have sired
Perfecto con V-ing
I could have been siring you could have been siring she could have been siring we could have been siring you could have been siring they could have been siring
Negación
Forma simple
I couldn't sire you couldn't sire she couldn't sire we couldn't sire you couldn't sire they couldn't sire
Forma con V-ing
I couldn't be siring you couldn't be siring she couldn't be siring we couldn't be siring you couldn't be siring they couldn't be siring
Perfecto
I couldn't have sired you couldn't have sired she couldn't have sired we couldn't have sired you couldn't have sired they couldn't have sired
Perfecto con V-ing
I couldn't have been siring you couldn't have been siring she couldn't have been siring we couldn't have been siring you couldn't have been siring they couldn't have been siring
Forma interrogativa
Forma simple
could I sire? could you sire? could she sire? could we sire? could you sire? could they sire?
Forma con V-ing
could I be siring? could you be siring? could she be siring? could we be siring? could you be siring? could they be siring?
Perfecto
could I have sired? could you have sired? could she have sired? could we have sired? could you have sired? could they have sired?
Perfecto con V-ing
could I have been siring? could you have been siring? could she have been siring? could we have been siring? could you have been siring? could they have been siring?
Forma interro-negativa
Forma simple
couldn't I sire? couldn't you sire? couldn't she sire? couldn't we sire? couldn't you sire? couldn't they sire?
Forma con V-ing
couldn't I be siring? couldn't you be siring? couldn't she be siring? couldn't we be siring? couldn't you be siring? couldn't they be siring?
Perfecto
couldn't I have sired? couldn't you have sired? couldn't she have sired? couldn't we have sired? couldn't you have sired? couldn't they have sired?
Perfecto con V-ing
couldn't I have been siring? couldn't you have been siring? couldn't she have been siring? couldn't we have been siring? couldn't you have been siring? couldn't they have been siring?