English verb conjugation
COULD SERVE

Regular verb: serve - served - served

Affirmation

Simple form	V-ing form
I could serve you could serve he could serve we could serve you could serve they could serve	I could be serving you could be serving he could be serving we could be serving you could be serving they could be serving
Perfect	V-ing perfect
I could have served you could have served he could have served we could have served you could have served they could have served	I could have been serving you could have been serving he could have been serving we could have been serving you could have been serving they could have been serving

Negation

Simple form	V-ing form
I couldn't serve you couldn't serve he couldn't serve we couldn't serve you couldn't serve they couldn't serve	I couldn't be serving you couldn't be serving he couldn't be serving we couldn't be serving you couldn't be serving they couldn't be serving
Perfect	V-ing perfect
I couldn't have served you couldn't have served he couldn't have served we couldn't have served you couldn't have served they couldn't have served	I couldn't have been serving you couldn't have been serving he couldn't have been serving we couldn't have been serving you couldn't have been serving they couldn't have been serving

Interrogative form

Simple form	V-ing form
could I serve? could you serve? could he serve? could we serve? could you serve? could they serve?	could I be serving? could you be serving? could he be serving? could we be serving? could you be serving? could they be serving?
Perfect	V-ing perfect
could I have served? could you have served? could he have served? could we have served? could you have served? could they have served?	could I have been serving? could you have been serving? could he have been serving? could we have been serving? could you have been serving? could they have been serving?

Interro-negative form

Simple form	V-ing form
couldn't I serve? couldn't you serve? couldn't he serve? couldn't we serve? couldn't you serve? couldn't they serve?	couldn't I be serving? couldn't you be serving? couldn't he be serving? couldn't we be serving? couldn't you be serving? couldn't they be serving?
Perfect	V-ing perfect
couldn't I have served? couldn't you have served? couldn't he have served? couldn't we have served? couldn't you have served? couldn't they have served?	couldn't I have been serving? couldn't you have been serving? couldn't he have been serving? couldn't we have been serving? couldn't you have been serving? couldn't they have been serving?