English verb conjugation
COULD SUBTEND

Regular verb: subtend - subtended - subtended

Affirmation

Simple form	V-ing form
I could subtend you could subtend he could subtend we could subtend you could subtend they could subtend	I could be subtending you could be subtending he could be subtending we could be subtending you could be subtending they could be subtending
Perfect	V-ing perfect
I could have subtended you could have subtended he could have subtended we could have subtended you could have subtended they could have subtended	I could have been subtending you could have been subtending he could have been subtending we could have been subtending you could have been subtending they could have been subtending

Negation

Simple form	V-ing form
I couldn't subtend you couldn't subtend he couldn't subtend we couldn't subtend you couldn't subtend they couldn't subtend	I couldn't be subtending you couldn't be subtending he couldn't be subtending we couldn't be subtending you couldn't be subtending they couldn't be subtending
Perfect	V-ing perfect
I couldn't have subtended you couldn't have subtended he couldn't have subtended we couldn't have subtended you couldn't have subtended they couldn't have subtended	I couldn't have been subtending you couldn't have been subtending he couldn't have been subtending we couldn't have been subtending you couldn't have been subtending they couldn't have been subtending

Interrogative form

Simple form	V-ing form
could I subtend? could you subtend? could he subtend? could we subtend? could you subtend? could they subtend?	could I be subtending? could you be subtending? could he be subtending? could we be subtending? could you be subtending? could they be subtending?
Perfect	V-ing perfect
could I have subtended? could you have subtended? could he have subtended? could we have subtended? could you have subtended? could they have subtended?	could I have been subtending? could you have been subtending? could he have been subtending? could we have been subtending? could you have been subtending? could they have been subtending?

Interro-negative form

Simple form	V-ing form
couldn't I subtend? couldn't you subtend? couldn't he subtend? couldn't we subtend? couldn't you subtend? couldn't they subtend?	couldn't I be subtending? couldn't you be subtending? couldn't he be subtending? couldn't we be subtending? couldn't you be subtending? couldn't they be subtending?
Perfect	V-ing perfect
couldn't I have subtended? couldn't you have subtended? couldn't he have subtended? couldn't we have subtended? couldn't you have subtended? couldn't they have subtended?	couldn't I have been subtending? couldn't you have been subtending? couldn't he have been subtending? couldn't we have been subtending? couldn't you have been subtending? couldn't they have been subtending?