I could attain you could attain she could attain we could attain you could attain they could attain
V-ing form
I could be attaining you could be attaining she could be attaining we could be attaining you could be attaining they could be attaining
Perfect
I could have attained you could have attained she could have attained we could have attained you could have attained they could have attained
V-ing perfect
I could have been attaining you could have been attaining she could have been attaining we could have been attaining you could have been attaining they could have been attaining
Negation
Simple form
I could not attain you could not attain she could not attain we could not attain you could not attain they could not attain
V-ing form
I could not be attaining you could not be attaining she could not be attaining we could not be attaining you could not be attaining they could not be attaining
Perfect
I could not have attained you could not have attained she could not have attained we could not have attained you could not have attained they could not have attained
V-ing perfect
I could not have been attaining you could not have been attaining she could not have been attaining we could not have been attaining you could not have been attaining they could not have been attaining
Interrogative form
Simple form
could I attain? could you attain? could she attain? could we attain? could you attain? could they attain?
V-ing form
could I be attaining? could you be attaining? could she be attaining? could we be attaining? could you be attaining? could they be attaining?
Perfect
could I have attained? could you have attained? could she have attained? could we have attained? could you have attained? could they have attained?
V-ing perfect
could I have been attaining? could you have been attaining? could she have been attaining? could we have been attaining? could you have been attaining? could they have been attaining?
Interro-negative form
Simple form
could I not attain? could you not attain? could she not attain? could we not attain? could you not attain? could they not attain?
V-ing form
could I not be attaining? could you not be attaining? could she not be attaining? could we not be attaining? could you not be attaining? could they not be attaining?
Perfect
could I not have attained? could you not have attained? could she not have attained? could we not have attained? could you not have attained? could they not have attained?
V-ing perfect
could I not have been attaining? could you not have been attaining? could she not have been attaining? could we not have been attaining? could you not have been attaining? could they not have been attaining?