English verb conjugation
COULD MACHINE

Regular verb: machine - machined - machined

Affirmation

Simple form	V-ing form
I could machine you could machine she could machine we could machine you could machine they could machine	I could be machining you could be machining she could be machining we could be machining you could be machining they could be machining
Perfect	V-ing perfect
I could have machined you could have machined she could have machined we could have machined you could have machined they could have machined	I could have been machining you could have been machining she could have been machining we could have been machining you could have been machining they could have been machining

Negation

Simple form	V-ing form
I couldn't machine you couldn't machine she couldn't machine we couldn't machine you couldn't machine they couldn't machine	I couldn't be machining you couldn't be machining she couldn't be machining we couldn't be machining you couldn't be machining they couldn't be machining
Perfect	V-ing perfect
I couldn't have machined you couldn't have machined she couldn't have machined we couldn't have machined you couldn't have machined they couldn't have machined	I couldn't have been machining you couldn't have been machining she couldn't have been machining we couldn't have been machining you couldn't have been machining they couldn't have been machining

Interrogative form

Simple form	V-ing form
could I machine? could you machine? could she machine? could we machine? could you machine? could they machine?	could I be machining? could you be machining? could she be machining? could we be machining? could you be machining? could they be machining?
Perfect	V-ing perfect
could I have machined? could you have machined? could she have machined? could we have machined? could you have machined? could they have machined?	could I have been machining? could you have been machining? could she have been machining? could we have been machining? could you have been machining? could they have been machining?

Interro-negative form

Simple form	V-ing form
couldn't I machine? couldn't you machine? couldn't she machine? couldn't we machine? couldn't you machine? couldn't they machine?	couldn't I be machining? couldn't you be machining? couldn't she be machining? couldn't we be machining? couldn't you be machining? couldn't they be machining?
Perfect	V-ing perfect
couldn't I have machined? couldn't you have machined? couldn't she have machined? couldn't we have machined? couldn't you have machined? couldn't they have machined?	couldn't I have been machining? couldn't you have been machining? couldn't she have been machining? couldn't we have been machining? couldn't you have been machining? couldn't they have been machining?