English verb conjugation
COULD EXTRUDE

Regular verb: extrude - extruded - extruded

Affirmation

Simple form	V-ing form
I could extrude you could extrude he could extrude we could extrude you could extrude they could extrude	I could be extruding you could be extruding he could be extruding we could be extruding you could be extruding they could be extruding
Perfect	V-ing perfect
I could have extruded you could have extruded he could have extruded we could have extruded you could have extruded they could have extruded	I could have been extruding you could have been extruding he could have been extruding we could have been extruding you could have been extruding they could have been extruding

Negation

Simple form	V-ing form
I couldn't extrude you couldn't extrude he couldn't extrude we couldn't extrude you couldn't extrude they couldn't extrude	I couldn't be extruding you couldn't be extruding he couldn't be extruding we couldn't be extruding you couldn't be extruding they couldn't be extruding
Perfect	V-ing perfect
I couldn't have extruded you couldn't have extruded he couldn't have extruded we couldn't have extruded you couldn't have extruded they couldn't have extruded	I couldn't have been extruding you couldn't have been extruding he couldn't have been extruding we couldn't have been extruding you couldn't have been extruding they couldn't have been extruding

Interrogative form

Simple form	V-ing form
could I extrude? could you extrude? could he extrude? could we extrude? could you extrude? could they extrude?	could I be extruding? could you be extruding? could he be extruding? could we be extruding? could you be extruding? could they be extruding?
Perfect	V-ing perfect
could I have extruded? could you have extruded? could he have extruded? could we have extruded? could you have extruded? could they have extruded?	could I have been extruding? could you have been extruding? could he have been extruding? could we have been extruding? could you have been extruding? could they have been extruding?

Interro-negative form

Simple form	V-ing form
couldn't I extrude? couldn't you extrude? couldn't he extrude? couldn't we extrude? couldn't you extrude? couldn't they extrude?	couldn't I be extruding? couldn't you be extruding? couldn't he be extruding? couldn't we be extruding? couldn't you be extruding? couldn't they be extruding?
Perfect	V-ing perfect
couldn't I have extruded? couldn't you have extruded? couldn't he have extruded? couldn't we have extruded? couldn't you have extruded? couldn't they have extruded?	couldn't I have been extruding? couldn't you have been extruding? couldn't he have been extruding? couldn't we have been extruding? couldn't you have been extruding? couldn't they have been extruding?