English verb conjugation
CAN DOUBT

Regular verb: doubt - doubted - doubted

Affirmation

Simple form	V-ing form
I can doubt you can doubt she can doubt we can doubt you can doubt they can doubt	I can be doubting you can be doubting she can be doubting we can be doubting you can be doubting they can be doubting
Perfect	V-ing perfect
I can have doubted you can have doubted she can have doubted we can have doubted you can have doubted they can have doubted	I can have been doubting you can have been doubting she can have been doubting we can have been doubting you can have been doubting they can have been doubting

Negation

Simple form	V-ing form
I can't doubt you can't doubt she can't doubt we can't doubt you can't doubt they can't doubt	I can't be doubting you can't be doubting she can't be doubting we can't be doubting you can't be doubting they can't be doubting
Perfect	V-ing perfect
I can't have doubted you can't have doubted she can't have doubted we can't have doubted you can't have doubted they can't have doubted	I can't have been doubting you can't have been doubting she can't have been doubting we can't have been doubting you can't have been doubting they can't have been doubting

Interrogative form

Simple form	V-ing form
can I doubt? can you doubt? can she doubt? can we doubt? can you doubt? can they doubt?	can I be doubting? can you be doubting? can she be doubting? can we be doubting? can you be doubting? can they be doubting?
Perfect	V-ing perfect
can I have doubted? can you have doubted? can she have doubted? can we have doubted? can you have doubted? can they have doubted?	can I have been doubting? can you have been doubting? can she have been doubting? can we have been doubting? can you have been doubting? can they have been doubting?

Interro-negative form

Simple form	V-ing form
can't I doubt? can't you doubt? can't she doubt? can't we doubt? can't you doubt? can't they doubt?	can't I be doubting? can't you be doubting? can't she be doubting? can't we be doubting? can't you be doubting? can't they be doubting?
Perfect	V-ing perfect
can't I have doubted? can't you have doubted? can't she have doubted? can't we have doubted? can't you have doubted? can't they have doubted?	can't I have been doubting? can't you have been doubting? can't she have been doubting? can't we have been doubting? can't you have been doubting? can't they have been doubting?