English verb conjugation
CAN SIRE

Regular verb: sire - sired - sired

Affirmation

Simple form	V-ing form
I can sire you can sire she can sire we can sire you can sire they can sire	I can be siring you can be siring she can be siring we can be siring you can be siring they can be siring
Perfect	V-ing perfect
I can have sired you can have sired she can have sired we can have sired you can have sired they can have sired	I can have been siring you can have been siring she can have been siring we can have been siring you can have been siring they can have been siring

Negation

Simple form	V-ing form
I can't sire you can't sire she can't sire we can't sire you can't sire they can't sire	I can't be siring you can't be siring she can't be siring we can't be siring you can't be siring they can't be siring
Perfect	V-ing perfect
I can't have sired you can't have sired she can't have sired we can't have sired you can't have sired they can't have sired	I can't have been siring you can't have been siring she can't have been siring we can't have been siring you can't have been siring they can't have been siring

Interrogative form

Simple form	V-ing form
can I sire? can you sire? can she sire? can we sire? can you sire? can they sire?	can I be siring? can you be siring? can she be siring? can we be siring? can you be siring? can they be siring?
Perfect	V-ing perfect
can I have sired? can you have sired? can she have sired? can we have sired? can you have sired? can they have sired?	can I have been siring? can you have been siring? can she have been siring? can we have been siring? can you have been siring? can they have been siring?

Interro-negative form

Simple form	V-ing form
can't I sire? can't you sire? can't she sire? can't we sire? can't you sire? can't they sire?	can't I be siring? can't you be siring? can't she be siring? can't we be siring? can't you be siring? can't they be siring?
Perfect	V-ing perfect
can't I have sired? can't you have sired? can't she have sired? can't we have sired? can't you have sired? can't they have sired?	can't I have been siring? can't you have been siring? can't she have been siring? can't we have been siring? can't you have been siring? can't they have been siring?