English verb conjugation
COULD MASH

Regular verb: mash - mashed - mashed

Affirmation

Simple form	V-ing form
I could mash you could mash he could mash we could mash you could mash they could mash	I could be mashing you could be mashing he could be mashing we could be mashing you could be mashing they could be mashing
Perfect	V-ing perfect
I could have mashed you could have mashed he could have mashed we could have mashed you could have mashed they could have mashed	I could have been mashing you could have been mashing he could have been mashing we could have been mashing you could have been mashing they could have been mashing

Negation

Simple form	V-ing form
I could not mash you could not mash he could not mash we could not mash you could not mash they could not mash	I could not be mashing you could not be mashing he could not be mashing we could not be mashing you could not be mashing they could not be mashing
Perfect	V-ing perfect
I could not have mashed you could not have mashed he could not have mashed we could not have mashed you could not have mashed they could not have mashed	I could not have been mashing you could not have been mashing he could not have been mashing we could not have been mashing you could not have been mashing they could not have been mashing

Interrogative form

Simple form	V-ing form
could I mash? could you mash? could he mash? could we mash? could you mash? could they mash?	could I be mashing? could you be mashing? could he be mashing? could we be mashing? could you be mashing? could they be mashing?
Perfect	V-ing perfect
could I have mashed? could you have mashed? could he have mashed? could we have mashed? could you have mashed? could they have mashed?	could I have been mashing? could you have been mashing? could he have been mashing? could we have been mashing? could you have been mashing? could they have been mashing?

Interro-negative form

Simple form	V-ing form
could I not mash? could you not mash? could he not mash? could we not mash? could you not mash? could they not mash?	could I not be mashing? could you not be mashing? could he not be mashing? could we not be mashing? could you not be mashing? could they not be mashing?
Perfect	V-ing perfect
could I not have mashed? could you not have mashed? could he not have mashed? could we not have mashed? could you not have mashed? could they not have mashed?	could I not have been mashing? could you not have been mashing? could he not have been mashing? could we not have been mashing? could you not have been mashing? could they not have been mashing?