English verb conjugation
COULD DOCTOR

Regular verb: doctor - doctored - doctored

Affirmation

Simple form	V-ing form
I could doctor you could doctor he could doctor we could doctor you could doctor they could doctor	I could be doctoring you could be doctoring he could be doctoring we could be doctoring you could be doctoring they could be doctoring
Perfect	V-ing perfect
I could have doctored you could have doctored he could have doctored we could have doctored you could have doctored they could have doctored	I could have been doctoring you could have been doctoring he could have been doctoring we could have been doctoring you could have been doctoring they could have been doctoring

Negation

Simple form	V-ing form
I couldn't doctor you couldn't doctor he couldn't doctor we couldn't doctor you couldn't doctor they couldn't doctor	I couldn't be doctoring you couldn't be doctoring he couldn't be doctoring we couldn't be doctoring you couldn't be doctoring they couldn't be doctoring
Perfect	V-ing perfect
I couldn't have doctored you couldn't have doctored he couldn't have doctored we couldn't have doctored you couldn't have doctored they couldn't have doctored	I couldn't have been doctoring you couldn't have been doctoring he couldn't have been doctoring we couldn't have been doctoring you couldn't have been doctoring they couldn't have been doctoring

Interrogative form

Simple form	V-ing form
could I doctor? could you doctor? could he doctor? could we doctor? could you doctor? could they doctor?	could I be doctoring? could you be doctoring? could he be doctoring? could we be doctoring? could you be doctoring? could they be doctoring?
Perfect	V-ing perfect
could I have doctored? could you have doctored? could he have doctored? could we have doctored? could you have doctored? could they have doctored?	could I have been doctoring? could you have been doctoring? could he have been doctoring? could we have been doctoring? could you have been doctoring? could they have been doctoring?

Interro-negative form

Simple form	V-ing form
couldn't I doctor? couldn't you doctor? couldn't he doctor? couldn't we doctor? couldn't you doctor? couldn't they doctor?	couldn't I be doctoring? couldn't you be doctoring? couldn't he be doctoring? couldn't we be doctoring? couldn't you be doctoring? couldn't they be doctoring?
Perfect	V-ing perfect
couldn't I have doctored? couldn't you have doctored? couldn't he have doctored? couldn't we have doctored? couldn't you have doctored? couldn't they have doctored?	couldn't I have been doctoring? couldn't you have been doctoring? couldn't he have been doctoring? couldn't we have been doctoring? couldn't you have been doctoring? couldn't they have been doctoring?