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