English verb conjugation
COULD MENSTRUATE

Regular verb: menstruate - menstruated - menstruated

Affirmation

Simple form	V-ing form
I could menstruate you could menstruate he could menstruate we could menstruate you could menstruate they could menstruate	I could be menstruating you could be menstruating he could be menstruating we could be menstruating you could be menstruating they could be menstruating
Perfect	V-ing perfect
I could have menstruated you could have menstruated he could have menstruated we could have menstruated you could have menstruated they could have menstruated	I could have been menstruating you could have been menstruating he could have been menstruating we could have been menstruating you could have been menstruating they could have been menstruating

Negation

Simple form	V-ing form
I couldn't menstruate you couldn't menstruate he couldn't menstruate we couldn't menstruate you couldn't menstruate they couldn't menstruate	I couldn't be menstruating you couldn't be menstruating he couldn't be menstruating we couldn't be menstruating you couldn't be menstruating they couldn't be menstruating
Perfect	V-ing perfect
I couldn't have menstruated you couldn't have menstruated he couldn't have menstruated we couldn't have menstruated you couldn't have menstruated they couldn't have menstruated	I couldn't have been menstruating you couldn't have been menstruating he couldn't have been menstruating we couldn't have been menstruating you couldn't have been menstruating they couldn't have been menstruating

Interrogative form

Simple form	V-ing form
could I menstruate? could you menstruate? could he menstruate? could we menstruate? could you menstruate? could they menstruate?	could I be menstruating? could you be menstruating? could he be menstruating? could we be menstruating? could you be menstruating? could they be menstruating?
Perfect	V-ing perfect
could I have menstruated? could you have menstruated? could he have menstruated? could we have menstruated? could you have menstruated? could they have menstruated?	could I have been menstruating? could you have been menstruating? could he have been menstruating? could we have been menstruating? could you have been menstruating? could they have been menstruating?

Interro-negative form

Simple form	V-ing form
couldn't I menstruate? couldn't you menstruate? couldn't he menstruate? couldn't we menstruate? couldn't you menstruate? couldn't they menstruate?	couldn't I be menstruating? couldn't you be menstruating? couldn't he be menstruating? couldn't we be menstruating? couldn't you be menstruating? couldn't they be menstruating?
Perfect	V-ing perfect
couldn't I have menstruated? couldn't you have menstruated? couldn't he have menstruated? couldn't we have menstruated? couldn't you have menstruated? couldn't they have menstruated?	couldn't I have been menstruating? couldn't you have been menstruating? couldn't he have been menstruating? couldn't we have been menstruating? couldn't you have been menstruating? couldn't they have been menstruating?