I could obturate you could obturate she could obturate we could obturate you could obturate they could obturate
V-ing form
I could be obturating you could be obturating she could be obturating we could be obturating you could be obturating they could be obturating
Perfect
I could have obturated you could have obturated she could have obturated we could have obturated you could have obturated they could have obturated
V-ing perfect
I could have been obturating you could have been obturating she could have been obturating we could have been obturating you could have been obturating they could have been obturating
Negation
Simple form
I couldn't obturate you couldn't obturate she couldn't obturate we couldn't obturate you couldn't obturate they couldn't obturate
V-ing form
I couldn't be obturating you couldn't be obturating she couldn't be obturating we couldn't be obturating you couldn't be obturating they couldn't be obturating
Perfect
I couldn't have obturated you couldn't have obturated she couldn't have obturated we couldn't have obturated you couldn't have obturated they couldn't have obturated
V-ing perfect
I couldn't have been obturating you couldn't have been obturating she couldn't have been obturating we couldn't have been obturating you couldn't have been obturating they couldn't have been obturating
Interrogative form
Simple form
could I obturate? could you obturate? could she obturate? could we obturate? could you obturate? could they obturate?
V-ing form
could I be obturating? could you be obturating? could she be obturating? could we be obturating? could you be obturating? could they be obturating?
Perfect
could I have obturated? could you have obturated? could she have obturated? could we have obturated? could you have obturated? could they have obturated?
V-ing perfect
could I have been obturating? could you have been obturating? could she have been obturating? could we have been obturating? could you have been obturating? could they have been obturating?
Interro-negative form
Simple form
couldn't I obturate? couldn't you obturate? couldn't she obturate? couldn't we obturate? couldn't you obturate? couldn't they obturate?
V-ing form
couldn't I be obturating? couldn't you be obturating? couldn't she be obturating? couldn't we be obturating? couldn't you be obturating? couldn't they be obturating?
Perfect
couldn't I have obturated? couldn't you have obturated? couldn't she have obturated? couldn't we have obturated? couldn't you have obturated? couldn't they have obturated?
V-ing perfect
couldn't I have been obturating? couldn't you have been obturating? couldn't she have been obturating? couldn't we have been obturating? couldn't you have been obturating? couldn't they have been obturating?