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