English verb conjugation
COULD INSTALL

Regular verb: install - installed - installed

Affirmation

Simple form	V-ing form
I could install you could install he could install we could install you could install they could install	I could be installing you could be installing he could be installing we could be installing you could be installing they could be installing
Perfect	V-ing perfect
I could have installed you could have installed he could have installed we could have installed you could have installed they could have installed	I could have been installing you could have been installing he could have been installing we could have been installing you could have been installing they could have been installing

Negation

Simple form	V-ing form
I couldn't install you couldn't install he couldn't install we couldn't install you couldn't install they couldn't install	I couldn't be installing you couldn't be installing he couldn't be installing we couldn't be installing you couldn't be installing they couldn't be installing
Perfect	V-ing perfect
I couldn't have installed you couldn't have installed he couldn't have installed we couldn't have installed you couldn't have installed they couldn't have installed	I couldn't have been installing you couldn't have been installing he couldn't have been installing we couldn't have been installing you couldn't have been installing they couldn't have been installing

Interrogative form

Simple form	V-ing form
could I install? could you install? could he install? could we install? could you install? could they install?	could I be installing? could you be installing? could he be installing? could we be installing? could you be installing? could they be installing?
Perfect	V-ing perfect
could I have installed? could you have installed? could he have installed? could we have installed? could you have installed? could they have installed?	could I have been installing? could you have been installing? could he have been installing? could we have been installing? could you have been installing? could they have been installing?

Interro-negative form

Simple form	V-ing form
couldn't I install? couldn't you install? couldn't he install? couldn't we install? couldn't you install? couldn't they install?	couldn't I be installing? couldn't you be installing? couldn't he be installing? couldn't we be installing? couldn't you be installing? couldn't they be installing?
Perfect	V-ing perfect
couldn't I have installed? couldn't you have installed? couldn't he have installed? couldn't we have installed? couldn't you have installed? couldn't they have installed?	couldn't I have been installing? couldn't you have been installing? couldn't he have been installing? couldn't we have been installing? couldn't you have been installing? couldn't they have been installing?