English verb conjugation
COULD MASTURBATE

Regular verb: masturbate - masturbated - masturbated

Affirmation

Simple form	V-ing form
I could masturbate you could masturbate he could masturbate we could masturbate you could masturbate they could masturbate	I could be masturbating you could be masturbating he could be masturbating we could be masturbating you could be masturbating they could be masturbating
Perfect	V-ing perfect
I could have masturbated you could have masturbated he could have masturbated we could have masturbated you could have masturbated they could have masturbated	I could have been masturbating you could have been masturbating he could have been masturbating we could have been masturbating you could have been masturbating they could have been masturbating

Negation

Simple form	V-ing form
I couldn't masturbate you couldn't masturbate he couldn't masturbate we couldn't masturbate you couldn't masturbate they couldn't masturbate	I couldn't be masturbating you couldn't be masturbating he couldn't be masturbating we couldn't be masturbating you couldn't be masturbating they couldn't be masturbating
Perfect	V-ing perfect
I couldn't have masturbated you couldn't have masturbated he couldn't have masturbated we couldn't have masturbated you couldn't have masturbated they couldn't have masturbated	I couldn't have been masturbating you couldn't have been masturbating he couldn't have been masturbating we couldn't have been masturbating you couldn't have been masturbating they couldn't have been masturbating

Interrogative form

Simple form	V-ing form
could I masturbate? could you masturbate? could he masturbate? could we masturbate? could you masturbate? could they masturbate?	could I be masturbating? could you be masturbating? could he be masturbating? could we be masturbating? could you be masturbating? could they be masturbating?
Perfect	V-ing perfect
could I have masturbated? could you have masturbated? could he have masturbated? could we have masturbated? could you have masturbated? could they have masturbated?	could I have been masturbating? could you have been masturbating? could he have been masturbating? could we have been masturbating? could you have been masturbating? could they have been masturbating?

Interro-negative form

Simple form	V-ing form
couldn't I masturbate? couldn't you masturbate? couldn't he masturbate? couldn't we masturbate? couldn't you masturbate? couldn't they masturbate?	couldn't I be masturbating? couldn't you be masturbating? couldn't he be masturbating? couldn't we be masturbating? couldn't you be masturbating? couldn't they be masturbating?
Perfect	V-ing perfect
couldn't I have masturbated? couldn't you have masturbated? couldn't he have masturbated? couldn't we have masturbated? couldn't you have masturbated? couldn't they have masturbated?	couldn't I have been masturbating? couldn't you have been masturbating? couldn't he have been masturbating? couldn't we have been masturbating? couldn't you have been masturbating? couldn't they have been masturbating?