English verb conjugation
COULD PROTECT

Regular verb: protect - protected - protected

Affirmation

Simple form	V-ing form
I could protect you could protect he could protect we could protect you could protect they could protect	I could be protecting you could be protecting he could be protecting we could be protecting you could be protecting they could be protecting
Perfect	V-ing perfect
I could have protected you could have protected he could have protected we could have protected you could have protected they could have protected	I could have been protecting you could have been protecting he could have been protecting we could have been protecting you could have been protecting they could have been protecting

Negation

Simple form	V-ing form
I couldn't protect you couldn't protect he couldn't protect we couldn't protect you couldn't protect they couldn't protect	I couldn't be protecting you couldn't be protecting he couldn't be protecting we couldn't be protecting you couldn't be protecting they couldn't be protecting
Perfect	V-ing perfect
I couldn't have protected you couldn't have protected he couldn't have protected we couldn't have protected you couldn't have protected they couldn't have protected	I couldn't have been protecting you couldn't have been protecting he couldn't have been protecting we couldn't have been protecting you couldn't have been protecting they couldn't have been protecting

Interrogative form

Simple form	V-ing form
could I protect? could you protect? could he protect? could we protect? could you protect? could they protect?	could I be protecting? could you be protecting? could he be protecting? could we be protecting? could you be protecting? could they be protecting?
Perfect	V-ing perfect
could I have protected? could you have protected? could he have protected? could we have protected? could you have protected? could they have protected?	could I have been protecting? could you have been protecting? could he have been protecting? could we have been protecting? could you have been protecting? could they have been protecting?

Interro-negative form

Simple form	V-ing form
couldn't I protect? couldn't you protect? couldn't he protect? couldn't we protect? couldn't you protect? couldn't they protect?	couldn't I be protecting? couldn't you be protecting? couldn't he be protecting? couldn't we be protecting? couldn't you be protecting? couldn't they be protecting?
Perfect	V-ing perfect
couldn't I have protected? couldn't you have protected? couldn't he have protected? couldn't we have protected? couldn't you have protected? couldn't they have protected?	couldn't I have been protecting? couldn't you have been protecting? couldn't he have been protecting? couldn't we have been protecting? couldn't you have been protecting? couldn't they have been protecting?