English verb conjugation
COULD DOCTOR

Regular verb: doctor - doctored - doctored

Affirmation

Simple form	V-ing form
I could doctor you could doctor she could doctor we could doctor you could doctor they could doctor	I could be doctoring you could be doctoring she 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 she 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 she 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 she 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 she 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 she 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 she 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 she doctor? could we doctor? could you doctor? could they doctor?	could I be doctoring? could you be doctoring? could she 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 she 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 she 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 she 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 she 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 she 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 she have been doctoring? couldn't we have been doctoring? couldn't you have been doctoring? couldn't they have been doctoring?