I can invest you can invest he can invest we can invest you can invest they can invest
V-ing form
I can be investing you can be investing he can be investing we can be investing you can be investing they can be investing
Perfect
I can have invested you can have invested he can have invested we can have invested you can have invested they can have invested
V-ing perfect
I can have been investing you can have been investing he can have been investing we can have been investing you can have been investing they can have been investing
Negation
Simple form
I cannot invest you cannot invest he cannot invest we cannot invest you cannot invest they cannot invest
V-ing form
I cannot be investing you cannot be investing he cannot be investing we cannot be investing you cannot be investing they cannot be investing
Perfect
I cannot have invested you cannot have invested he cannot have invested we cannot have invested you cannot have invested they cannot have invested
V-ing perfect
I cannot have been investing you cannot have been investing he cannot have been investing we cannot have been investing you cannot have been investing they cannot have been investing
Interrogative form
Simple form
can I invest? can you invest? can he invest? can we invest? can you invest? can they invest?
V-ing form
can I be investing? can you be investing? can he be investing? can we be investing? can you be investing? can they be investing?
Perfect
can I have invested? can you have invested? can he have invested? can we have invested? can you have invested? can they have invested?
V-ing perfect
can I have been investing? can you have been investing? can he have been investing? can we have been investing? can you have been investing? can they have been investing?
Interro-negative form
Simple form
can I not invest? can you not invest? can he not invest? can we not invest? can you not invest? can they not invest?
V-ing form
can I not be investing? can you not be investing? can he not be investing? can we not be investing? can you not be investing? can they not be investing?
Perfect
can I not have invested? can you not have invested? can he not have invested? can we not have invested? can you not have invested? can they not have invested?
V-ing perfect
can I not have been investing? can you not have been investing? can he not have been investing? can we not have been investing? can you not have been investing? can they not have been investing?