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