English verb conjugation
COULD CLEAN

Regular verb: clean - cleaned - cleaned

Affirmation

Simple form	V-ing form
I could clean you could clean he could clean we could clean you could clean they could clean	I could be cleaning you could be cleaning he could be cleaning we could be cleaning you could be cleaning they could be cleaning
Perfect	V-ing perfect
I could have cleaned you could have cleaned he could have cleaned we could have cleaned you could have cleaned they could have cleaned	I could have been cleaning you could have been cleaning he could have been cleaning we could have been cleaning you could have been cleaning they could have been cleaning

Negation

Simple form	V-ing form
I couldn't clean you couldn't clean he couldn't clean we couldn't clean you couldn't clean they couldn't clean	I couldn't be cleaning you couldn't be cleaning he couldn't be cleaning we couldn't be cleaning you couldn't be cleaning they couldn't be cleaning
Perfect	V-ing perfect
I couldn't have cleaned you couldn't have cleaned he couldn't have cleaned we couldn't have cleaned you couldn't have cleaned they couldn't have cleaned	I couldn't have been cleaning you couldn't have been cleaning he couldn't have been cleaning we couldn't have been cleaning you couldn't have been cleaning they couldn't have been cleaning

Interrogative form

Simple form	V-ing form
could I clean? could you clean? could he clean? could we clean? could you clean? could they clean?	could I be cleaning? could you be cleaning? could he be cleaning? could we be cleaning? could you be cleaning? could they be cleaning?
Perfect	V-ing perfect
could I have cleaned? could you have cleaned? could he have cleaned? could we have cleaned? could you have cleaned? could they have cleaned?	could I have been cleaning? could you have been cleaning? could he have been cleaning? could we have been cleaning? could you have been cleaning? could they have been cleaning?

Interro-negative form

Simple form	V-ing form
couldn't I clean? couldn't you clean? couldn't he clean? couldn't we clean? couldn't you clean? couldn't they clean?	couldn't I be cleaning? couldn't you be cleaning? couldn't he be cleaning? couldn't we be cleaning? couldn't you be cleaning? couldn't they be cleaning?
Perfect	V-ing perfect
couldn't I have cleaned? couldn't you have cleaned? couldn't he have cleaned? couldn't we have cleaned? couldn't you have cleaned? couldn't they have cleaned?	couldn't I have been cleaning? couldn't you have been cleaning? couldn't he have been cleaning? couldn't we have been cleaning? couldn't you have been cleaning? couldn't they have been cleaning?