English verb conjugation
COULD SEVER

Regular verb: sever - severed - severed

Affirmation

Simple form	V-ing form
I could sever you could sever he could sever we could sever you could sever they could sever	I could be severing you could be severing he could be severing we could be severing you could be severing they could be severing
Perfect	V-ing perfect
I could have severed you could have severed he could have severed we could have severed you could have severed they could have severed	I could have been severing you could have been severing he could have been severing we could have been severing you could have been severing they could have been severing

Negation

Simple form	V-ing form
I couldn't sever you couldn't sever he couldn't sever we couldn't sever you couldn't sever they couldn't sever	I couldn't be severing you couldn't be severing he couldn't be severing we couldn't be severing you couldn't be severing they couldn't be severing
Perfect	V-ing perfect
I couldn't have severed you couldn't have severed he couldn't have severed we couldn't have severed you couldn't have severed they couldn't have severed	I couldn't have been severing you couldn't have been severing he couldn't have been severing we couldn't have been severing you couldn't have been severing they couldn't have been severing

Interrogative form

Simple form	V-ing form
could I sever? could you sever? could he sever? could we sever? could you sever? could they sever?	could I be severing? could you be severing? could he be severing? could we be severing? could you be severing? could they be severing?
Perfect	V-ing perfect
could I have severed? could you have severed? could he have severed? could we have severed? could you have severed? could they have severed?	could I have been severing? could you have been severing? could he have been severing? could we have been severing? could you have been severing? could they have been severing?

Interro-negative form

Simple form	V-ing form
couldn't I sever? couldn't you sever? couldn't he sever? couldn't we sever? couldn't you sever? couldn't they sever?	couldn't I be severing? couldn't you be severing? couldn't he be severing? couldn't we be severing? couldn't you be severing? couldn't they be severing?
Perfect	V-ing perfect
couldn't I have severed? couldn't you have severed? couldn't he have severed? couldn't we have severed? couldn't you have severed? couldn't they have severed?	couldn't I have been severing? couldn't you have been severing? couldn't he have been severing? couldn't we have been severing? couldn't you have been severing? couldn't they have been severing?