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 couldn't mash you couldn't mash he couldn't mash we couldn't mash you couldn't mash they couldn't mash	I couldn't be mashing you couldn't be mashing he couldn't be mashing we couldn't be mashing you couldn't be mashing they couldn't be mashing
Perfect	V-ing perfect
I couldn't have mashed you couldn't have mashed he couldn't have mashed we couldn't have mashed you couldn't have mashed they couldn't have mashed	I couldn't have been mashing you couldn't have been mashing he couldn't have been mashing we couldn't have been mashing you couldn't have been mashing they couldn't 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
couldn't I mash? couldn't you mash? couldn't he mash? couldn't we mash? couldn't you mash? couldn't they mash?	couldn't I be mashing? couldn't you be mashing? couldn't he be mashing? couldn't we be mashing? couldn't you be mashing? couldn't they be mashing?
Perfect	V-ing perfect
couldn't I have mashed? couldn't you have mashed? couldn't he have mashed? couldn't we have mashed? couldn't you have mashed? couldn't they have mashed?	couldn't I have been mashing? couldn't you have been mashing? couldn't he have been mashing? couldn't we have been mashing? couldn't you have been mashing? couldn't they have been mashing?