English verb conjugation
CAN SERVE

Regular verb: serve - served - served

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can I not serve? can you not serve? can he not serve? can we not serve? can you not serve? can they not serve?	can I not be serving? can you not be serving? can he not be serving? can we not be serving? can you not be serving? can they not be serving?
Perfect	V-ing perfect
can I not have served? can you not have served? can he not have served? can we not have served? can you not have served? can they not have served?	can I not have been serving? can you not have been serving? can he not have been serving? can we not have been serving? can you not have been serving? can they not have been serving?