I could invest you could invest he could invest we could invest you could invest they could invest
V-ing form
I could be investing you could be investing he could be investing we could be investing you could be investing they could be investing
Perfect
I could have invested you could have invested he could have invested we could have invested you could have invested they could have invested
V-ing perfect
I could have been investing you could have been investing he could have been investing we could have been investing you could have been investing they could have been investing
Negation
Simple form
I couldn't invest you couldn't invest he couldn't invest we couldn't invest you couldn't invest they couldn't invest
V-ing form
I couldn't be investing you couldn't be investing he couldn't be investing we couldn't be investing you couldn't be investing they couldn't be investing
Perfect
I couldn't have invested you couldn't have invested he couldn't have invested we couldn't have invested you couldn't have invested they couldn't have invested
V-ing perfect
I couldn't have been investing you couldn't have been investing he couldn't have been investing we couldn't have been investing you couldn't have been investing they couldn't have been investing
Interrogative form
Simple form
could I invest? could you invest? could he invest? could we invest? could you invest? could they invest?
V-ing form
could I be investing? could you be investing? could he be investing? could we be investing? could you be investing? could they be investing?
Perfect
could I have invested? could you have invested? could he have invested? could we have invested? could you have invested? could they have invested?
V-ing perfect
could I have been investing? could you have been investing? could he have been investing? could we have been investing? could you have been investing? could they have been investing?
Interro-negative form
Simple form
couldn't I invest? couldn't you invest? couldn't he invest? couldn't we invest? couldn't you invest? couldn't they invest?
V-ing form
couldn't I be investing? couldn't you be investing? couldn't he be investing? couldn't we be investing? couldn't you be investing? couldn't they be investing?
Perfect
couldn't I have invested? couldn't you have invested? couldn't he have invested? couldn't we have invested? couldn't you have invested? couldn't they have invested?
V-ing perfect
couldn't I have been investing? couldn't you have been investing? couldn't he have been investing? couldn't we have been investing? couldn't you have been investing? couldn't they have been investing?