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