English verb conjugation
COULD SINGE

Regular verb: singe - singed - singed

Affirmation

Simple form	V-ing form
I could singe you could singe he could singe we could singe you could singe they could singe	I could be singing you could be singing he could be singing we could be singing you could be singing they could be singing
Perfect	V-ing perfect
I could have singed you could have singed he could have singed we could have singed you could have singed they could have singed	I could have been singing you could have been singing he could have been singing we could have been singing you could have been singing they could have been singing

Negation

Simple form	V-ing form
I couldn't singe you couldn't singe he couldn't singe we couldn't singe you couldn't singe they couldn't singe	I couldn't be singing you couldn't be singing he couldn't be singing we couldn't be singing you couldn't be singing they couldn't be singing
Perfect	V-ing perfect
I couldn't have singed you couldn't have singed he couldn't have singed we couldn't have singed you couldn't have singed they couldn't have singed	I couldn't have been singing you couldn't have been singing he couldn't have been singing we couldn't have been singing you couldn't have been singing they couldn't have been singing

Interrogative form

Simple form	V-ing form
could I singe? could you singe? could he singe? could we singe? could you singe? could they singe?	could I be singing? could you be singing? could he be singing? could we be singing? could you be singing? could they be singing?
Perfect	V-ing perfect
could I have singed? could you have singed? could he have singed? could we have singed? could you have singed? could they have singed?	could I have been singing? could you have been singing? could he have been singing? could we have been singing? could you have been singing? could they have been singing?

Interro-negative form

Simple form	V-ing form
couldn't I singe? couldn't you singe? couldn't he singe? couldn't we singe? couldn't you singe? couldn't they singe?	couldn't I be singing? couldn't you be singing? couldn't he be singing? couldn't we be singing? couldn't you be singing? couldn't they be singing?
Perfect	V-ing perfect
couldn't I have singed? couldn't you have singed? couldn't he have singed? couldn't we have singed? couldn't you have singed? couldn't they have singed?	couldn't I have been singing? couldn't you have been singing? couldn't he have been singing? couldn't we have been singing? couldn't you have been singing? couldn't they have been singing?